In a large skillet, brown ground beef and onion over medium-high heat until ground beef is fully cooked, seasoning with salt and pepper as needed. Drain grease.
Mix in taco seasoning and water and cook for 1-2 minutes over heat.
Spray slow cooker with non-stick cooking spray.
Add cooked meat, tomatoes, chilies, salsa, beef broth, and corn to the slow cooker. Mix all together.
Place lid on top of slow cooker and cook on HIGH heat for 3-4 hours or on LOW heat for 5-6 hours.
Remove lid, stir in pasta, and put lid back on. Switch the heat to HIGH heat. Cook the shells for 20-25 minutes in the slow cooker or until they reach the desired doneness.
Remove lid and sprinkle cheese on top. Stir in cheese until it melts and taco pasta is creamy.
Serve topped with your favorite toppings (pico de gallo, guacamole, lettuce, cilantro, sliced olives, etc).
Instant Pot Instructions
Plug in your Instant Pot and push "saute" button. Add in ground beef and onion and brown until fully cooked.
Add in taco seasoning, pasta, salsa, chilis, and chicken broth. Stir to combine. Place lid on Instant Pot and seal. Make sure that your valve is in the "seal" position and not the "vent" position.
Push the "manual" button and then set for 5 minutes. The Instant Pot will take about 10 minutes to pressurize and then it will start the 5 minute cooking time.
Once the 5 minutes are up, do a quick release (move the valve from "seal" to "vent") and let all the pressure out. Once the steam has stopped coming out of the vent and the pin in the lid has dropped, remove the lid.
Stir the pasta, add in the cheese and stir until completely combined and cheese is melted. Add salt and pepper as needed and serve.
If desired, top with your favorite taco toppings.
Notes
Want to make this even more cheesy? Swap out .5 cup of the shredded cheese with .5 cup jarred cheese queso dip (I usually use the Tostitos brand and it's delicious).Cooking time for Instant Pot version is approximately the following: 5 minutes prep time, 15 minutes cook time, 10 minutes prep time, for a total of 30 minutes.