Cook the Spaghetti. Bring a large pot of salted water to a boil. Cook the spaghetti according to the package directions until al dente. Drain well and set aside.

Brown the Beef & Vegetables. In a large skillet over medium-high heat, add the ground beef, diced onion, and bell pepper. Cook until the beef is browned and the vegetables are softened, about 6–8 minutes. Drain off any excess grease.

Season the Mixture. Sprinkle the taco seasoning over the beef mixture and stir well to coat evenly.

Make the Cheesy Rotel Sauce. Add the diced tomatoes with green chilies (undrained), chicken broth, Velveeta cubes, and shredded cheddar cheese to the skillet. Reduce the heat to low and stir gently until the cheeses melt completely, forming a smooth, creamy sauce.

Combine Everything. Add the cooked spaghetti noodles to the skillet and toss until the pasta is fully coated in the cheesy sauce.

Serve & Enjoy. Serve hot, topped with extra shredded cheese or chopped cilantro if desired