Heat oil on medium high, cook cardamom and cinnamon for 1 min, then onion, ginger and garlic until onion is translucent.
Add spices, sauté 1 min, lentils and 2 cups water. Simmer 15 min on medium with lid on. Add chickpeas, stock, remaining water, salt and baking soda. Simmer uncovered on medium/ medium high 30 minutes until reduced and thickened into a thin gravy (lentils breakdown and thicken the sauce).
