In a large pot over medium heat, add a drizzle of oil, and cook the sausage until browned, breaking into small bits.
Add in the onion, celery, carrots, and zucchini. Cook for 5 minutes, or until slightly softened. Stir in the garlic and cook an additional minute.
Stir in the tomato paste, lentils, oregano, basil, and thyme. Stir and cook for 30 seconds.
Pour in the beef stock, and season with salt and pepper. Bring to a boil, then turn the heat down to a simmer. Cover, and cook for 30-35 minutes, or until the lentils are soft and cooked through.
Serve with some fresh herbs and parmesan.
