In a food processor or blender, pulse the the onion, tomatoes, ginger, garlic and chili until almost pureed (I prefer a little texture). Pour into sieve over bowl, and using spoon or spatula, press to extract excess water. Discard water and set aside.
Heat oil in a Dutch oven or deep skillet with lid. Fry the cumin seeds with bay leaves for 1 minute. Pour in pureed vegetables, salt, turmeric, chili powder, garam masala and ground coriander. Stir and cook on low for 8 minutes.
Add the potatoes, cauliflower and 3 cups of water, stir to combine. Bring to a boil and cover. Turn heat to low and simmer 15 minutes, until vegetables are fork tender.
Remove from heat, add frozen peas and fenugreek leaves. Stir and season to taste if salt needed.
Serve as a side dish with or over rice as a main dish.