Turkish* spinach and lentil soup

Soften 1 large onion, chopped, in some olive oil. Stir in 1/2 cup bulgar wheat, 3 cloves garlic (finely chopped) and 1/2 tsp cayenne pepper and cook a bit more until it starts to look brown. Add about 8 chopped tomatoes, some rosemary, and some parsley if you have it and poke about until the tomatoes start to soften. Add lentils (measure 1 cup then cook) - big grey ones today, though I have made it with posh Puy ones - plus their cooking liquid, then a pot (500 ml) of chicken stock. Simmer for 15-20 minutes then stir in a couple of cups of roughly chopped (well-washed) spinach. Season, and serve with a dollop of yogurt and more chopped parsley.

*I have no idea why it is Turkish, but this is what the original recipe said