Prepare the lentils: rinse them in cold running water to remove impurities;
Soak them overnight in plenty of water (they are easier to digest);
Prepare the sautéed vegetables: cut the onion, celery, and carrot into small pieces;
In a pan, heat the oil along with the bay leaves;
Add the onion, the celery, and then the carrots and stir well;
Sauté over medium-high heat; be careful as the onion shouldn’t get too brown;
Add the tomato paste and then the sauce;
Cook for a few minutes allowing the flavors to meld together;
Add the lentils and stir well with a wooden spoon. Cook for about 15 minutes;
Reduce the heat to low and cover with a lid;
Season with salt, pepper, and red pepper flakes;
In another pot bring the water to a rolling boil;
When the water boils, add a generous handful of coarse salt; then add the pasta and cook according to the package instructions;
Drain the pasta and add it into the lentil sauce;
Stir well to combine, cook for a couple of minutes over high heat, and serve hot. It is ideally paired with a crisp green salad.