Vegetarian Dal Makhani (Kidney Beans & Lentils in Spicy Cream Sauce)

This is a classic Punjabi dish - a very rich, satisfying dish that's full of protein...

1 cup whole black lentils (cooked)
2 cups kidney beans, pre-cooked
1 cup vegetable stock

1 onion, chopped finely
1 tomato, diced
4 cloves garlic, minced
1/2 TB ginger, grated
1 TB tomato paste
2 TB heavy cream
1 tsp. red chili powder
1/2 tsp. ground cumin
1/2 tsp. ground coriander
1/2 tsp. amchur (mango powder) (optional)
1 TB butter
2 TB oil
1/2 tsp. salt

Heat oil in a pan and saute onions until lightly browned. Add salt, chili powder, garlic, ginger, and tomato paste and fry for 30 seconds. Add tomatoes and cook for 2 more minutes. Add cooked lentils and 1 cup stock and simmer until stock is slightly reduced and lentils are completely tender. Add cream, cumin, coriander, amchur, butter, and kidney beans and cook 5 more minutes on low heat.