Heat a large pan over medium heat. Add the olive oil, minced onion, salt, and pepper. Saute over medium heat until the onion is translucent, about 4-6 minutes. Reduce heat to low and season with dried oregano, basil, chili flakes, and dried garlic. Add the tomato sauce and let simmer while you prepare the cashew sauce.

To make the cashew sauce, add the cashews, water, and nutritional yeast to a small blender. Blend on high until fully smooth. Add the cashew sauce to the tomato mixture, along with the cooked lentils. Stir until combined. Keep on low until heated through. Serve over your pasta of choice.