Prepare the Aromatic Base: Roughly chop the onions and pulse them in a food processor until finely minced. In a medium-sized saucepan, melt the niter kibbeh over medium heat. Add the minced onions, garlic, and ginger to the pot. Cook the mixture for about 15 minutes, stirring frequently, until it breaks down into a soft, almost puréed consistency. Reduce heat if it begins to stick or brown too quickly.
Bloom the Spices: Once the onion mixture is well-cooked, add the black pepper, berbere spice, turmeric, and paprika. Stir constantly for 1 minute to toast the spices and release their full aroma. This step deepens the flavor of the stew.
Add Lentils and Liquids: Rinse the lentils under cold water using a fine-mesh sieve until the water runs mostly clear. Add the lentils to the pot along with the tomato paste, vegetable broth, and a pinch of salt. Stir well to combine all the ingredients.
Simmer Until Tender: Bring the stew to a gentle boil over medium heat, then immediately reduce the heat to low. Cover the pot and allow the mixture to simmer for about 35 minutes, or until the lentils are soft and the stew thickens to your desired consistency. Stir occasionally to prevent sticking, and add a splash of broth if it becomes too thick.
Garnish and Serve: Once the stew is ready, taste and adjust salt as needed. Ladle into bowls and garnish with fresh cilantro sprigs. Serve warm with injera or rice for a complete and authentic meal.