In a bowl, soak lentils in cold water for at least 30 minutes. Place them in a medium pot, add 3 cups of water. Bring to a boil over medium heat, let it simmer on low heat until lentils are just tender. Drain the lentils, set aside.
Lentils soaked in water
Cut the onions in half, thinly slice them. In the you have cooked lentils sauté onions in olive oil until golden brown, about 3 minutes. Add 2 cups of water, bring to a boil. When it starts to boil, add drained lentils, bulgur, tomato paste, crushed red peppers (optional), salt and pepper. Stir gently. Bring to a boil and let it gently simmer over low heat. Cook until bulgur is tender and water is absorbed.
Serve with meat, chicken or fish. You can add chunks of cooked meat or chicken, making it a hearty dish by itself.