Walk into a Thai kitchen — whether it belongs to a street food vendor in Bangkok or a home cook in Chiang Mai — and the first thing you notice is not the wok, or the mortar and pestle, or the neat rows of sauces and pastes. It is the herbs. Bundles of lemongrass leaning against the counter. A pile of kaffir lime leaves releasing their oil into the air at the slightest touch. Coriander arrived with its roots still attached, because in Thai cooking the roots matter as much as the leaves.
This abundance of fresh aromatics is not incidental. It is the defining characteristic of Thai cuisine — the thing that separates it most clearly from other Asian food traditions, and the reason Thai food tastes the way it does: alive, layered, and impossibly fragrant.
Fresh, Not Dried
Most of the world's great spice-driven cuisines — Indian, Moroccan, Persian — build their depth from dried spices: cumin, coriander seed, turmeric, cardamom. These are extraordinary ingredients, capable of extraordinary flavour. But Thai cooking takes a fundamentally different approach. Where other cuisines reach for the spice jar, Thai cooking reaches for something still living.
Lemongrass is used fresh, not dried. Galangal is sliced from the root, not shaken from a tin. Kaffir lime leaves are torn at the last moment so their oils are at full intensity when they hit the dish. Coriander root is pounded in the mortar alongside garlic and chilli to form the base of innumerable sauces and pastes. The result is a flavour that is brighter, more immediate, and more vivid than anything dried spices alone can produce — food that smells as good as it tastes, and tastes exactly as good as it smells.
Understanding these herbs — what they are, what they contribute, and how to use them — is the single most useful step any home cook can take toward cooking Thai food that tastes genuinely authentic.
Lemongrass
Lemongrass is perhaps the most recognisable Thai herb in the world, and for good reason. Its flavour — citrusy, floral, and faintly grassy, with a clean freshness that no other ingredient can replicate — appears in everything from curry pastes and soups to marinades and dipping sauces.
The part that carries the flavour is the lower, pale section of the stalk — the outer leaves are too tough and fibrous to eat, but they can be bruised and added to broths and soups to infuse their aroma. For pastes and finely prepared dishes, the inner stalk is sliced very thinly or pounded in a mortar, releasing the essential oils that give Thai cooking its signature fragrance.
In tom yum, lemongrass provides the backbone of the broth's aroma. In green and red curry pastes, it adds a citrus note that balances the earthiness of galangal and the heat of chilli. In gai yang marinade, it perfumes the chicken with a fragrance that intensifies beautifully over the heat of the grill.
Lemongrass is one of those ingredients that, once you understand it, you will want to use constantly — and one of the reasons ONOFF's curry pastes taste as authentic as they do is that organic lemongrass is right there at the heart of every one of them.
Galangal
Galangal is frequently described as a cousin of ginger, which is accurate but somewhat misleading — the two plants are related, but galangal has a character entirely its own. Where ginger is warm, sharp, and familiar, galangal is more complex: earthy, slightly piney, with a medicinal quality that sounds unappealing in description and is absolutely essential in practice.
It is the ingredient that gives tom kha gai — coconut and galangal chicken soup — its distinctive depth, and the reason that trying to substitute ginger for galangal in a Thai recipe produces something that tastes noticeably, unmistakably wrong. Galangal is not ginger. The two are not interchangeable, and any recipe that tells you otherwise is sacrificing authenticity for convenience.
Fresh galangal is sliced or pounded for use in pastes and soups. It is also one of those ingredients with genuine functional value beyond flavour — used for centuries across Southeast Asia for its digestive and anti-inflammatory properties. In Thai curry pastes, including ONOFF's full range, galangal plays a structural role: it is one of the ingredients that gives the paste its body and its depth, working quietly beneath the more prominent notes of lemongrass and chilli.
Kaffir Lime Leaves
Kaffir lime leaves are visually distinctive — their unusual double-lobed shape, two leaves joined end to end, makes them immediately recognisable once you know what you are looking for. Their fragrance is extraordinary: intensely citrusy and floral, with a complexity that far exceeds what the fruit itself delivers. The moment you tear a kaffir lime leaf, the oils in the leaf are released, and the aroma that fills the air is one of the most beautiful things in Thai cooking.
In curry pastes, the zest of the kaffir lime fruit is used rather than the leaf — sharper and more concentrated, it provides the citrus backbone of green and red pastes. The leaves themselves are used in soups, curries, and stir fries, either left whole to infuse and then removed before eating, or sliced into very fine strips and used as a garnish where their fragrance and slight chew are part of the eating experience.
ONOFF's dried Thai Lime Leaf is a practical and authentic way to bring this ingredient into your kitchen — the drying process concentrates the oils, so the flavour is present and correct even when fresh leaves are not available. They are worth keeping in your pantry as a constant.
Holy Basil
Of the three basil varieties used in Thai cooking — holy basil, Thai sweet basil, and lemon basil — holy basil is the most important and the least substitutable. It has a peppery, slightly clove-like flavour with an intensity that Italian basil simply does not have, and it is the non-negotiable ingredient in pad krapow — the holy basil stir fry that is arguably Thailand's most eaten everyday dish.
The name krapow is the Thai word for holy basil, which tells you everything you need to know about how central this herb is to the dish. Without holy basil, pad krapow is just a minced meat stir fry. With it, it becomes something with genuine character — aromatic, slightly peppery, deeply savoury, and entirely itself.
Holy basil wilts quickly once added to a hot pan, which is why it is always added at the very last moment, off the heat, so the residual warmth releases its fragrance without destroying it. It is one of the few herbs in Thai cooking that is genuinely irreplaceable — though Thai sweet basil is a closer substitute than anything from a Western kitchen.
Coriander Root
This is the Thai herb that surprises people most — not because coriander is unfamiliar, but because most of the world discards the root and uses only the leaves. In Thai cooking, the priority is almost inverted. The root and the lower stems are pounded into curry pastes and marinades, where they contribute an earthy, slightly nutty depth that the leaves cannot provide. The leaves themselves are used as a fresh garnish, scattered over finished dishes for their bright, citrusy fragrance.
Coriander root is the quiet foundation of many Thai pastes and sauces — present in the background, doing structural work that you would notice immediately if it were absent. It is one of the reasons that a Thai curry paste made from scratch in a mortar and pestle tastes different from one made in a food processor: the pounding of the root, along with the galangal and lemongrass, releases compounds that blending alone does not fully extract.
If you buy coriander with the roots still attached — which is worth seeking out — keep the roots in the freezer between uses. They last well and are always ready when you need them.
Putting It Together
What makes Thai herbs so remarkable is not any one of them individually, but what happens when they work together. Lemongrass and kaffir lime zest provide the citrus top notes. Galangal adds the earthy, medicinal depth. Coriander root brings the nutty base. Chilli brings the heat. And the result — when these ingredients are properly prepared and properly balanced — is a flavour profile that is simultaneously complex and coherent, layered and harmonious, unlike anything else in world cuisine.
This is the foundation on which ONOFF's curry pastes are built. Organic lemongrass, organic galangal, organic kaffir lime, organic coriander — each ingredient sourced with care, prepared authentically, and brought together in a paste that carries the genuine character of Thai cooking into your kitchen wherever you are in the world.
The herbs are the soul of Thai cuisine. Everything else is built on top of them.
Tod Mun Pla — Thai Fish Cakes
Cooks in 25 minutesTod mun pla are one of Thailand's great street food classics — golden, slightly springy fish cakes fragrant with red curry paste and finely shredded kaffir lime leaves, served with a sweet and tangy dipping sauce. They are the kind of snack that disappears from the plate before you have finished cooking the last batch. The kaffir lime leaf is not a garnish here — it is woven into every cake, releasing its citrusy, floral oil with every bite and giving tod mun pla a character that no other fish cake in the world quite matches. Simple to make, deeply satisfying, and unmistakably Thai.
