In your large pot or Dutch oven, heat the olive oil over medium heat. Add the diced onion and red pepper, cooking until softened, about 3-4 minutes. Stir in the minced garlic and cook for an additional minute, until fragrant.
Add the ground beef to the pot, breaking it up with your spoon. Cook until browned and cooked through, about 5-7 minutes. Drain any excess fat if necessary.
Stir in the tomato paste, taco seasoning, and beef bouillon powder, mixing well to combine all the flavors. Cook for about 2 minutes to toast the spices.
Add the diced tomatoes and red enchilada sauce to the pot. Stir to combine and bring to a gentle simmer.
Pour in the chicken broth, followed by the spaghetti. Make sure the pasta is submerged in the liquid. Increase the heat to bring it to a boil, then reduce the heat to a simmer. Cover and cook for about 10-12 minutes, stirring occasionally, until the spaghetti is al dente and the sauce has thickened.
Once the spaghetti is cooked, remove the pot from the heat. Stir in half of the shredded cheddar cheese until melted. Top with the remaining cheese and cover for a few minutes until the cheese is bubbly and melted.
Spoon the Taco Spaghetti into bowls, and enjoy your hearty, cheesy one-pot meal! Optional toppings could include sour cream, chopped green onions, or avocado for an extra layer of flavor.
