Whizz onion, garlic, ginger and tomatoes into a puree.
Heat oil in a large pan. Add spices, fry for a few seconds, add purée and yeast extract. Bubble for 2 mins, then add coconut milk, chickpeas and spinach. Cook approx. 10 minutes to thicken. Season to taste. Squeeze over lemon and sprinkle on sesame seeds and cashews. Serve with rice.