Cook pasta as instructed on the package.

While the pasta is cooking, pour the olive oil into a hot pan and sauté the onion, garlic, celery, and carrot.

Then, add the lentils, the broth, the bay leaf, and tomato sauce. Allow the lentils to cook while the broth is reduced, and consistency gets sauce-like.

Season with salt and pepper, add the pasta, mix it all well, and allow the flavors to integrate before serving.