The finished recipe. Lentil Bolognese with SpaghettiIngredients 1 to 6. Two tins, drained (600 g) Cooked lentils (Cooked weight, green or brown. A pouch is already this.). 150 g Onion. 150 g Carrot. 2 sticks, about 80 g Celery. 200 g Mushrooms (Chopped small, they disappear into the sauce and do the job mince would.). Two tins (800 g) Chopped tomatoes, tinnedIngredients 7 to 12. 40 g Tomato purée. 15 g Olive oil. 3 cloves, about 9 g Garlic. 200 g Vegetable stock (Made up from a cube or a pot.). 1 tsp Dried oregano. 300 g dry spaghetti Pasta (Dry weight. Cooked, it is about 2.2 times heavier.)Step 1. Chop the onion, carrot and celery finely and cook them in the oil over a low heat for 15 minutes without colouring.Step 2. Turn the heat up, add the mushrooms and cook until their liquid has gone. Stir in the garlic and purée and fry for two minutes.Step 3. Add the tomatoes, stock, lentils and oregano. Simmer uncovered for 45 minutes, stirring now and then, until the sauce is thick and dark.Step 4. Cook the spaghetti in salted water, drain, and toss with the sauce and a splash of the pasta water.