Heat oil in a pan. Add fenugreek seeds and let it temper on medium heat for 30 secs. Add crushed garlic, onion and salt, stir often until slightly brown/caramalised (add a little water if you feel it is sticking to the pan). Add turmeric and chilli powder and stir for 1 minute on lowish heat. Add all the various tomato combinations, stir and leave to soften on medium-low heat for 20 mins.