Bring a large pot of salted water to a boil. Add the bowtie pasta and cook until tender but still slightly firm in the center. Drain thoroughly and set aside.

Heat the olive oil in a large skillet over medium-high heat. Add the ground beef and cook, breaking it up with a spoon, until browned and fully cooked. Drain off any excess grease.

Stir in the chopped onion and cook for a few minutes until softened. Add the minced garlic and cook just until fragrant.

Pour in the marinara sauce and stir in the condensed cream of mushroom soup and sour cream. Sprinkle in the dried Italian herbs, salt, and black pepper. Mix well and let the sauce simmer gently for about 10 minutes, stirring occasionally, so the flavors blend together.

Add the drained bowtie pasta to the skillet and toss until evenly coated in the creamy meat sauce.

If using, stir in 1/2 cup of the cheddar cheese and 1/4 cup of the mozzarella. Continue stirring until the cheese melts and the sauce becomes creamy and smooth.

Transfer the pasta mixture to a serving dish. If using, sprinkle the remaining cheddar and mozzarella over the top. Let it sit for a few minutes so the cheese softens and melts slightly before serving.