Cook pasta according to package directions; drain and keep warm.
Cook bacon in a large skillet until crisp. Drain bacon, reserving 1 tablespoon drippings in skillet. Crumble bacon, and set aside.
Sauté garlic and onion in reserved drippings until tender. Add Dijon mustard, collard greens, and tomato; reduce heat to medium, and cook 10 minutes.
Add pepper; pour over pasta, tossing gently to coat. Top with crumbled bacon and cheese.