Turn the Instant Pot to Sauté (Normal/Medium). Add the ground beef and cook, breaking it up with a wooden spoon, for 4–5 minutes, until mostly browned.
1 lb ground beef
Stir in the diced onion and minced garlic. Cook for another 2–3 minutes, until the onion is softened and fragrant. If there is a lot of grease, carefully spoon out some, leaving about 1–2 tablespoons in the pot.
1 medium yellow onion, 3 cloves garlic
Pour in about 1/4 cup of the beef broth and scrape up any browned bits stuck to the bottom of the pot with a wooden spoon to prevent a Burn warning.
1 3/4 cups low-sodium beef broth
Stir in the diced bell pepper, frozen corn, and black beans (if using), distributing them evenly through the beef mixture.
1 cup bell pepper, 1 cup frozen corn kernels, 15 oz black beans
Sprinkle in the salt, black pepper, chili powder, cumin, smoked paprika, oregano, and red pepper flakes (if using). Stir until the mixture is well coated and fragrant.
1 1/2 teaspoons kosher salt, 1/2 teaspoon black pepper, 1 1/2 teaspoons chili powder, 1 teaspoon ground cumin, 1 teaspoon smoked paprika, 1/2 teaspoon dried oregano, 1/4 teaspoon crushed red pepper flakes
Sprinkle the rinsed rice evenly over the beef and vegetable mixture, but do not stir. Gently pour the remaining beef broth over the rice, making sure all the grains are moistened while keeping the rice mostly on top.
1 cup long-grain white rice, 1 3/4 cups low-sodium beef broth
Pour the canned diced tomatoes with their juices over the rice, spreading them lightly across the surface. Do not stir; keeping the tomatoes on top helps prevent scorching.
14.5 oz diced tomatoes
Secure the Instant Pot lid and set the valve to Sealing. Select Manual or Pressure Cook on High pressure for 8 minutes.
When the cook time is complete, let the pressure release naturally for 5 minutes. Then carefully switch the valve to Venting to quick release the remaining steam. Open the lid. Some liquid on top is normal.
Gently fluff the rice and stir everything together until well combined. Taste and adjust salt and pepper if needed.
1 1/2 teaspoons kosher salt, 1/2 teaspoon black pepper
Sprinkle the shredded cheese evenly over the top of the hot mixture. Close the lid (no need to seal or cook) and let it sit for 2–3 minutes, until the cheese is melted.
1 1/2 cups shredded cheese
Top with chopped cilantro or parsley if desired. Serve hot, with sour cream or Greek yogurt on the side for added creaminess.
1/4 cup fresh cilantro or parsley, sour cream or Greek yogurt