In a Dutch oven over medium heat, add the olive oil and the onions. Cook until soft, about 5-6 minutes.
Stir in the garlic, salt and pepper, cumin, onion powder, paprika, oregano, and cayenne pepper. Cook, while stirring, until the garlic is fragrant, about 1 minute.
Stir the corn flour together with 2 tbsp of cold water (in a separate small bowl) until it's dissolved. Pour into the pot. Cook, stirring continuously, for 1 minute.
Slowly pour in the chicken stock while stirring constantly. Use the spoon to incorporate the flour into the stock and to scrape the brown bits from the bottom of the pan. You'll notice the liquid getting thicker.
Add in the cannellini beans, chiles, corn kernels, and chicken. Bring to a boil and then reduce to a simmer.
Simmer for 20-25 minutes, stirring occasionally.
Stir in the heavy cream and serve hot with tortilla chips, avocado, and sour cream.