Chicken curry for a large party

2 tbsp coriander seeds

1 tbsp cumin seeds

4 tbsp vegetable oil

1.2kg red onions (cut into large chunks)

200g garlic, peeled

3 tbsp turmeric

2kg potatoes (peeled and cut into cubes)

4 stalks lemon grass (can be bought in larger supermarkets or Asian markets)

2kg chicken meat (boneless breast or thighs from the butcher)

2 tbsp red chilli powder

1 tbsp salt

1 tsp sugar

2-3 x 400ml tinned coconut milk

Coriander leaves, roughly torn for garnish

Sesame seeds, for garnish (optional)

Cooked basmati rice (allow for 75g per person)