On stove: Using a heavy bottomed pot, heat the olive oil on medium high heat, then add the shallots and garlic, sautéing until softened. Add the beef and pork, stirring regularly, and breaking apart large chunks, until cooked through. Add the rest of the ingredients (except corn), turn the temperature down and simmer for 45-60 minutes, stirring occasionally. Add the corn within the last 5 minutes.
In Instant Pot: Set the pot to Sauté, add the oil and sauté the shallots and garlic until softened. Add the beef and pork,stirring regularly, and breaking apart large chunks, until cooked through. Add the rest of the ingredients (except corn), set the pot to Meat/Stew, and close under sealing for 15-25 minutes. Flip back to Sauté and add the corn, stirring for a few minutes until the corn is cooked.
Once done, serve with preferred toppings, like avocado, sour cream, shredded cheese and a squeeze of fresh lime juice.