Begin by setting your Instant Pot to the sauté function. Add the canola oil and let it heat up for a minute. Once hot, add the diced yellow onion and sauté until it becomes translucent, about 3-4 minutes. Stir in the minced garlic and cook for an additional 30 seconds, or until fragrant.
Add the ground beef to the pot. Use a wooden spoon to break it up and cook until it’s browned and cooked through, about 5-7 minutes. Drain any excess fat if necessary.
Stir in the Worcestershire sauce, taco seasoning, and red pepper flakes, if using. Mix well to coat the beef evenly with these flavorful ingredients.
Pour in the chunky salsa and beef broth, stirring to combine everything. Scrape up any browned bits from the bottom of the pot to add even more flavor.
Add the shell pasta to the pot, ensuring it is submerged in the liquid. Close the lid and set the valve to sealing. Select the manual or pressure cook setting and cook on high pressure for 4 minutes.
Once the cooking time is up, perform a quick release by carefully turning the valve to venting. Open the lid and stir in the shredded cheddar cheese. Mix until the cheese is melted and creamy.
Spoon the Cheesy Instant Pot Taco Pasta into bowls and serve warm. Optionally, top with chopped cilantro, diced tomatoes, or sour cream for an extra touch.