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
1 red onion	thinly sliced
1 clove garlic
2 tsp 0.01 l 10 ml ²⁄₃ tbsp 0.042 cup 0.018 pint ready-prepared ginger
1 tsp 0.005 l 5 ml ¹⁄₃ tbsp 0.021 cup 0.009 pint ready-chopped chillies
200g ¹⁄₅kg 0.441lb 7.05oz chopped tomatoes
50ml 0.05l 3 ¹⁄₃tbsp 10tsp 0.211cup 0.088pint water
200g ¹⁄₅kg 0.441lb 7.05oz chicken	cubed
2 tsp 0.01 l 10 ml ²⁄₃ tbsp 0.042 cup 0.018 pint garam masala
3 tbsp 0.045 l 45 ml 9 tsp 0.19 cup 0.079 pint yogurt
1 handful coriander leaves	roughly chopped