Bombay potato frittata

Name: Bombay potato frittata
Ingredients: 4 new potatoes, sliced into 5mm rounds; 100g baby spinach, chopped; 1 tbsp rapeseed oil; 1 onion, halved and sliced; 1 large garlic clove, finely grated; ½ tsp ground coriander; ½ tsp ground cumin; ¼ tsp black mustard seeds; ¼ tsp turmeric; 3 tomatoes, roughly chopped; 2 large eggs; ½ green chilli, deseeded and finely chopped; 1 small bunch of coriander, finely chopped; 1 tbsp mango chutney; 3 tbsp fat-free Greek yogurt