In a medium saucepan, saute the shallot and ginger in the olive oil over medium heat until the shallot is soft. Add the garlic and the Berbere spice, and stir to combine. Add the lentils and cook, stirring, for a couple of minutes.
Add the tomatoes and broth, bring to a boil, then lower the heat and simmer, covered, until the lentils are soft, about 25 minutes. Stir occasionally and add more liquid if the lentils are drying out.
Add salt and pepper to taste. Serve with a dollop of yogurt and garnish with cilantro (optional).