Pour cooked ful into a medium saucepan and heat over medium-high heat. Add chopped garlic, red lentils, broth or reserved liquid, cumin and chopped tomatoes.
Reduce heat to medium and stir occasionally, until everything starts to come together and the red lentils become tender, about 12 minutes.
Stir and smoosh until you get the consistency you like. Some people like it totally creamy, others more on the beany side. Squeeze in lemon juice and stir in parsley.
Add a drizzle of olive oil, but to eat like an Egyptian, allow each person to salt his own ful.
Recipe doubles easily. Serve warm or at room temperature.
Covered and refrigerated, it keeps up to a week and reheats nicely.