Peel and finely dice the onion. Peel the garlic and press it through the garlic press. Clean, wash and dice the tomatoes. Pat the chicken breast fillet dry and cut into cubes.
Heat the oil in a pan and fry the meat for 4-5 minutes while turning, then add the onion and garlic, continue to fry for about 2 minutes. Dust with curry and sweat briefly while stirring. Add the diced tomatoes and continue cooking for about 3-4 minutes. Deglaze with coconut milk, season and simmer for about 10 minutes.
Sort the spinach, wash and shake dry. Add the spinach to the chicken and let it collapse. Season to taste with salt and pepper.
Serve the chicken curry with basmati rice or naan bread.