To make the satay spice paste, blend lemongrass, onion, garlic, coriander, chilli powder, turmeric, fennel seeds, cumin, salt, and dark brown sugar to a fine puree.
To make the peanut sauce, grind peanuts, then combine with satay spice paste, coconut milk, dark brown sugar, tamarind paste, chilli powder, water, and salt in a saucepan and simmer until thickened.
Marinate chicken with satay spice paste, skewer chicken, drizzle with oil, and grill until cooked.
Serve chicken skewers with peanut sauce, cucumber, and red onion.
