Boil the lentils according to the instructions on the packaging.
Add minced onion and diced garlic to a skillet with a little bit of water. In the meantime peel and chop the carrots in small pieces and add these to the skillet.
Chop the celery and add it to the skillet.
Chop the yellow squash and add to the skillet.
Chop the mushrooms in small pieces and add these to the skillet as well.
Add the salt at this step to enhance the flavor. Cook for about 10 minutes adding a little bit of water if needed.
Strain the cooked lentils and add them to the veggie mixture.
Add the tomato sauce, tomato paste and the spices and stir. Simmer for 2-3 minutes. The sauce is done.
Cook the pasta according to the instructions on the packaging. Rinse the pasta and add to a plate together with the desired amount of sauce.
Notes
Use the immersion blender if you prefer an homogeneous paste.