Heat the avocado oil in a large thick-bottomed pot such as a large Dutch oven over medium-high heat on the stove top.
Add the yellow onion and sauté, stirring occasionally, until the onion has softened, about 5 minutes.
Add the ground venison to the soup pot and brown the meat for a few minutes, breaking it into smaller chunks with a rubber spatula or wooden spoon.
Stir in the remaining ingredients (bell peppers, jalapeno, garlic, chili powder, diced tomatoes, black beans, beef stock, pure maple syrup, and sea salt) until everything is well-combined. Cover the pot and bring it to a full boil.
Once boiling, reduce the heat to medium-low or low heat and continue cooking for at least 20 minutes (ideally one hour if you have the time). The longer the chili cooks, the deeper the flavors will be. Stir the chili occasionally while it cooks.
Taste the chili for flavor and add more salt, chili powder, or pure maple syrup to your personal taste.
Serve chili in big bowls with your favorite toppings, such as sour cream (or Greek yogurt), grated cheese, chopped red onions, green onions, cilantro, tortilla chips, etc.