Heat a large pot over medium heat and add the olive oil.
Once hot, add the onion, carrot, celery, and mushrooms. Add a generous pinch of salt and pepper and saute for about 10 minutes, stirring frequently, until soft and fragrant.
Add the garlic and saute for another 1-2 minutes.
Add the basil, oregano, and tomato paste. Saute for another minute.
Add the balsamic, Worcestershire, lentils, marinara, and vegetable broth. Stir and bring to a simmer.
Reduce the heat to medium low and cover the pot with a lid. Simmer for about 1 hour, stirring every 10 minutes, or until the lentils are cooked through completely. Taste and add more salt as desired.