Chop the venison and pork fat into relatively uniform cubes that will fit into your meat grinder. Alternatively, you can pulse the meat and fat in a food processor in 2-cup batches. Be careful not to overprocess. You want the mixture to have some texture. Add the wine, salt, garlic, pepper, fennel seeds, and fennel pollen, if using, and mix thoroughly with very clean hands. The most important thing to remember here is to keep everything very cold. In a sauté pan over medium heat, cook a tablespoon or so of the mixture, taste, and adjust the seasonings. Cover and refrigerate immediately for 8 hours or overnight.