In a large skillet over medium heat, brown the ground beef until almost cooked through (just a little pink). Add the onion and pepper and continue to cook until no longer pink. Stir in the taco seasoning. Taste the mixture and adjust seasoning and salt and pepper as desired. Add the tomatoes and cauliflower rice and stir to combine. Stir in the broth and bring to a simmer. Reduce the heat to medium low and cook until the cauliflower rice begins to soften, 8 to 10 minutes. Sprinkle the skillet with the cheese and cover. Let cook until the cheese is melted, 3 or 4 minutes. Remove from heat and top with your favorite toppings like sour cream, avocado, and chopped cilantro.