First-order Type-I Curry - Cooking like a Boss

A generic, tasty curry recipe which is about as quick to make as a jar curry but has actual flavour. Stolen from BBC Good Food.

oil		fry until soft	fry briefly	bring to boil	cover on medium-high for 5-6 minutes or chicken cooked	simmer and stir in
3 ¹⁄₂ red onion	thinly sliced
3 ¹⁄₂ clove garlic
7 tsp 0.035 l 35 ml 2 ¹⁄₃ tbsp 0.148 cup 0.062 pint ready-prepared ginger
3 ¹⁄₂ tsp 0.018 l 17 ¹⁄₂ ml 1 ¹⁄₆ tbsp 0.074 cup 0.031 pint ready-chopped chillies
700g 0.7kg 1.54lb 24.7oz chopped tomatoes
175ml 0.175l 11 ²⁄₃tbsp 35tsp 0.74cup 0.308pint water
700g 0.7kg 1.54lb 24.7oz chicken	cubed
7 tsp 0.035 l 35 ml 2 ¹⁄₃ tbsp 0.148 cup 0.062 pint garam masala
10 ¹⁄₂ tbsp 0.158 l 157 ¹⁄₂ ml 31 ¹⁄₂ tsp 0.666 cup 0.277 pint yogurt
3 ¹⁄₂ handful coriander leaves	roughly chopped