set instant pot to 'sauté'. add the olive oil and onions and sauté for 4-5 minutes, until onions are soft and transluscent.
add the ground beef to the pot with the worcestershire sauce, and break it up with a spatula. Sauté for 3-4 additional minutes, until cooked through. add 1-2 cups of stock to the pan.
add the rest of the stock, diced tomatoes, green chilies, corn, black beans, taco seasoning and bell peppers.
cook on high pressure for 5 minutes. when the cooking cycle has completed, allow the Instant Pot to sit for 10 minutes, before carefully releasing the remaining pressure.
top soup with shredded cheese, tortilla strips, cilantro and avocado, or your favorite toppings!