Bring the lentils to a boil over medium heat in 1 ½ litres of water. Let it cook as you continue with the rest of the recipe. Sprinkle about 1/2 tbsp. salt in the water with the lentils. Once the water is boiling, reduce the heat and let it simmer for 20 minutes or until the lentils are completely soft. Let the lentils drain. Taste and add some extra salt if necessary. Do not overcook the lentils.
Preheat your oven at 190 °C.
Meanwhile, melt 1 tbsp. oil in another large pot over medium heat. Fry the sausages until they turn brown on all sides for about 5 minutes or more depending on the type of sausage you have chosen.
Remove the fried sausages from the pot and place them on a plate.
Melt the second tablespoon oil and add the onion, carrots, celery and green pepper. Cook for about 5 minutes with the lid on the pot, stirring occasionally. Spice with salt. Once the vegetables are soft and the onion is glassy, add the garlic. Stir and cook for another 2 minutes. Sprinkle the flour over everything and stir until the flour is completely absorbed by the vegetables and the oil.
Add the Cubetti and cooked lentils to the pot and stir well to mix everything. Cook for approx. 5 minutes, until the water of the tomatoes has boiled a little and has become thicker.
Cut the sausages into bite-sized pieces and put them back into the pot. Stir. Taste and add extra salt if necessary. You can already serve the stew or choose to sprinkle your favourite grated cheese over it. In that case, broil the stew in the preheated oven for 20 minutes or until the cheese has melted.