To make the taco meat, in a large skillet heat the oil on medium-low heat and add the bell pepper, jalapeño, and onion. While stirring occasionally, cook until the onion is translucent, about 5 minutes. Add the garlic and cook for 30 more seconds.
Add the ground beef to the skillet, along with the cumin, chili powder, salt, pepper, and cayenne. Stir until everything is well combined and then cook the ground beef for 15 more minutes, or until browned. Taste and adjust seasonings. Turn off the heat and drain any excess grease.
Meanwhile, to make the guacamole, mash together the avocado, lime juice, and cilantro. Add salt to taste.
To make the queso, in a saucepot heat the oil on medium-low heat and add the jalapeño and onion. While stirring occasionally, cook until the onion is translucent, about 5 minutes. Add the garlic and cook for 30 more seconds.
Leaving on the heat, stir in the cumin, black pepper, and cornstarch until the dry ingredients are well combined with the vegetables. Pour in the chicken broth and while stirring cook until the sauce has thickened, which should happen in a couple of minutes.
Turn the heat down to low and working in batches, slowly stir in a handful of the cheese. After it’s melted into the sauce, repeat the process until all the cheese is added. Stir in the tomatoes, adjust seasonings, and add salt to taste.
This makes a lot of queso, so you can either serve it in individual bowls or in a larger dish, such as a 9-inch square dish. To assemble, layer along the bottom of the dish the taco meat, then pour in the queso and then top with the guacamole and sour cream. Serve warm with chips.