Prepare Horizon macaroni and cheese according to package directions.

Heat olive oil in a large skillet over medium-high heat. Add turkey, red onion, and red bell pepper. Saute, breaking up turkey, until turkey is cooked through and onions are translucent.

Stir in black beans, taco seasoning, prepared macaroni and cheese, and shredded cheese. Continue to cook until cheese is melted.

Serve topped with sliced green onions.