Set your Instant Pot to its sauté function. Once hot, add the olive oil and brown one side of the ground beef for 4-5 minutes before breaking apart with a spatula.
Add the diced peppers and a pinch of salt to the Instant Pot and stir together with the ground beef. Continue cooking until the beef is fully cooked and the peppers soften, another 5-6 minutes.
Add the frozen cauliflower rice, corn, taco seasoning, and crushed tomatoes. Stir everything together before adding the beef broth.
Seal the Instant Pot and cook with high pressure for 20 minutes. Vent immediately and serve. (Although this soup is better the longer it simmers.)
Garnish with shredded cheese, pico de gallo, light sour cream or fat free Greek yogurt, and serve with tortilla chips.