Heat 3 tablespoons of niter kibbeh in a medium pot until melted.
Add the finely diced onion and cook over medium-high heat for about 8 to 10 minutes until the onions turn golden brown.
Mix in the minced garlic, chopped tomato, tomato paste, and 1 tablespoon of berbere and cook, stirring, for 5 to 7 minutes, adjusting the heat to avoid burning.
Pour in the rinsed red lentils, chicken broth, and salt, then bring everything to a boil.
Lower the heat to a simmer, cover the pot, and cook the lentils for 40 minutes, stirring now and then, adding extra broth if necessary until they are tender.
Blend in the remaining tablespoon of niter kibbeh and berbere, allowing the stew to simmer for a few additional minutes.
Adjust seasoning with salt to your taste.
Serve warm, ideally alongside traditional Ethiopian injera.