1. Clean the lentils, removing any stones or other legumes. Rinse them, drain, and place them in a pot. Add the water, and when it starts to boil, add the carrot, celery, stock cube, and bay leaf, and boil for 5 minutes. Add the orzo pasta. Stir occasionally so the orzo doesn't stick to the bottom of the pot.
2. When the mixture boils, reduce the heat to medium and continue boiling for about 15 minutes. Meanwhile, peel the onions, cut them in half, and then slice them into strips. In a frying pan, add the olive oil and sauté the onions. Let them cook until they turn a dark brown color (but don't let them burn), about 12 minutes.
3. Next, add the tomato paste and stir it on the bottom of the pot to release its aromas. Add the crushed tomatoes and the concentrated tomato juice. Let the sauce boil for 3 - 4 minutes, then add the salt and pepper. Pour the sauce into the lentil mixture.
4. Continue boiling until the sauce thickens and the orzo and lentils are tender, about 15 - 20 minutes. It is important to stir the dish so the orzo doesn't stick to the bottom of the pot.
5. Serve the lentils hot. They go perfectly with olives, a raw onion, and freshly baked bread.
