Heat 1tbsp oil in a medium sauce pan; add onions and green chilies, cook till onions are translucent, about 3~4 minutes.
Add ginger+garlic paste and cook for 1 minute. Next add tomato puree and berbere spice, cook for 2~3 minutes.
Add 3 cups of water (or vegetable stock or a combination of water and stock), bring the mixture to a boil. Lower the heat and simmer covered until lentils are cooked through, tender and creamy, this will take about 15~20 minutes.
Season with salt, mix well and serve hot over injera or as is.