Measure 4 tablespoons of niter kibbeh (Ethiopian spiced butter) and 2 tablespoons of berbere spice blend. Reserve a quarter of the butter and half the berbere.
Melt the remaining butter in a pot over medium-high heat. Cook 1 large yellow onion, finely diced, for 8-10 minutes, until golden.
Add 3 garlic cloves, minced, 1 finely chopped Roma tomato, 3 tablespoons of tomato paste and the unreserved berbere. Cook for 5-7 minutes, lowering the heat if needed.
Add 1 cup of rinsed red lentils, 2½ cups of vegetable stock, and 1 teaspoon of salt. Bring to a boil, then cover and simmer gently for about 40 minutes, until soft. Stir occasionally and add a little water if needed.
Stir in the reserved butter and berbere. Simmer for 2 minutes and adjust the salt.
