Step 3
Meanwhile, prepare the curry paste. Dry fry the mustard and coriander seeds in a pan on a low heat for 1 minute. Add to a blender, along with the onion, garlic, lemongrass, chili, and tomatoes. Blitz till fine or leave chunkier if that's how you prefer it. Option to use a pestle and mortar and remove the tomato skins if you like.