Peel and chop the onion. Dab meat dry and cut into thin strips. Fry in hot oil all around for about 5 minutes. Fry the onion briefly. Season with salt and pepper. Take out.
Briefly roast trail mix in hot frying fat. Dust with flour and curry and sauté briefly while stirring. Deglaze with 350 ml water and bring to the boil. Simmer for about 5 minutes while stirring. Add frozen peas and cook for 2-3 minutes.
Add the meat again and heat briefly. Stir in yoghurt (do not cook any more!). Season to taste with salt and pepper. Garnish with coriander. Serve with flatbread or rice.