Bring a large pot of salted water to boil for the pasta. Cook the pasta until al dente, according to the package directions, stirring occasionally.
While the pasta cooks, heat the olive oil in a skillet over medium heat. Add garlic + onion; cook until fragrant, translucent, + softened, 4-5 minutes.
Add the tomato, stir, + cook until it releases a little moisture, about 3 minutes.
Add the lentil soup + tomato paste, stir well, + cook until heated through + bubbling. Remove from the heat, add the balsamic vinegar, + salt + pepper to taste.
When the pasta is done, drain, toss with a tiny bit of olive oil, + return to the pot. Stir about half of the lentil mixture into the pasta so the pasta is well-coated in sauce.
Divide the pasta between 4 bowls, and top each bowl with a quarter of the remaining lentil mixture. Top with a generous serving of freshly-grated parmesan + chopped parsley. Stir, and enjoy!