1. Make the koshari. Heat Dutch oven on medium heat. Add oil. When oil is hot, add chopped onions. Sprinkle onions with pinch of salt and stir well. Cook until onions are translucent and soft. Add lentils, brown rice and garlic clove to pot. Mix thoroughly to coat lentils and rice with oil. Cook for about 5 minutes, stirring constantly. Add 4 cups of water. Bring to a boil. Reduce heat, place lid on pot, and simmer, for about 1 hour. Stir occasionally, adding more water, if needed. Lentils should be tender and rice, slightly firm (al dente). Add garbanzos and mix well. Cook 5 more minutes or until garbanzo beans are heated through. Add salt and pepper to taste.
2. While lentils and rice simmer, make tomato sauce. In saucepan, heat oil on medium heat. Add chopped garlic and cook until aromatic, about 10 seconds. Add crushed tomatoes, ground cumin, salt, pepper, vinegar, cinnamon, jalapeno and red pepper flakes. Stir well to combine. Bring to a boil. Reduce heat and simmer uncovered for about 45 minutes or until sauce thickens. Stir occasionally. Taste and adjust seasoning.
3. While koshari and sauce simmer, make or prepare your choice of toppings.
4. To serve, mound the koshari in an individual soup or pasta bowl, spoon tomato sauce over the koshari, and garnish with caramelized onions or other toppings. Serve immediately with pita bread. Makes 4 to 6 servings.