Step 1: Brown the Ground Beef: Turn the Instant Pot to the "Saute" function. Add the ground beef and cook until browned, breaking it up with a spoon. Drain off any excess grease.
Step 2: Saute Aromatics: Add the chopped onion and minced garlic to the Instant Pot. Cook until the onion is softened and translucent, about 3-5 minutes.
Step 3: Add Remaining Ingredients: Stir in the crushed tomatoes, tomato sauce, kidney beans, green bell pepper, chili powder, cumin, oregano, cayenne pepper (if using), and beef broth. Season with salt and pepper to taste.
Step 4: Pressure Cook: Close the Instant Pot lid and seal the valve. Cook on "Manual" or "Pressure Cook" mode for 15 minutes.
Step 5: Natural Pressure Release: Allow the Instant Pot to naturally release pressure for 10 minutes, then manually release any remaining pressure.
Step 6: Serve and Garnish: Open the Instant Pot and stir the chili. Serve hot, garnished with shredded cheese, sour cream, and chopped green onions, if desired.
Optional: For a thicker chili, mix 1 tablespoon of cornstarch with 2 tablespoons of cold water. Stir the slurry into the chili after cooking and let it sit for a few minutes to thicken. Other variations include adding a can of diced tomatoes or substituting ground turkey for ground beef.