Chop 1 green chili and make thin slices of the other one. Chop the onions into rings.
In a Pan, add 2 teaspoons oil and shallow fry/cook a third of the onion rings, 1 sliced green chili, a tablespoon of cilantro leaves and a few thin slices of red bell pepper(optional) on medium heat, for 4 to 6 minutes, on medium heat. Remove from pan and keep aside.
In the same pan, add the remaining 1 tsp oil, remaining onions, chopped green chili and the spices(coriander, cumin, fenugreek seeds, pomegranate seeds and turmeric powder). Cook on medium heat with occasional stirring till the onions are golden.
Add in the ginger and mint leaves and cook for a minute.
Take off heat and Blend the onion mixture with a little lemon juice or water into a thick puree.
In the pan, add the butter, onion puree, salt and sugar to taste.
Add in the chopped tempeh and mix well to coat. Cook covered for 20-25 minutes, stirring occasionally, until the puree thickens to almost dry and browns a bit.
Add in a cup of water and mix. Adjust for salt and spice and cook for another 5-10 minutes to get the desired consistency of the curry.
Serve hot topped with the fried onion rings, chili, pepper mixture. Add a tsp of vegan butter for richer curry. Serve with any Indian Flat bread or basmati rice.