Rinse and drain the lentils.
Heat the oil in a large pot over medium heat.
Add the onion and carrot then cook for around 3 minutes.
Slice then add the mushrooms and continue to cook until the carrots are soft.
Add chopped rosemary and crushed walnuts, then stir together.
Add the garlic, balsamic vinegar, and the umami seasoning and give it another stir.
Now add the tomatoes, lentils, tomato paste, and fresh cherry tomatoes, then stir again.
Simmer the sauce for about 20 minutes, until it thickens.
Bring a large pot of salted water to a boil.
Cook the pasta according to the instructions on the package.
Drain and add the pasta to the pan with the sauce.
Serve with fresh basil to provide an added meaty taste, and crushed red peppercorns for added oomph, and if you have vegan parmesan grate some on top to complete your meal.