Optional ingredients: 2 tbsp agave syrup (or more, if a sweeter taste is desired) finely chopped hot peppers, to taste
1 large sauteing pan
Finely chop the onion, zucchini, red pepper, and mince the garlic. Saute them all in a little olive oil, until the onions are soft.
Add the meat and thyme and cook over a medium heat until the meat is nearly done (bison will take less time than beef, so keep a watch if you're using it for the first time).
Add the tomatoes, ketchup, Worcestershire sauce, and agave. Use a spoon to break up the meat and stir well.
Cook over medium low heat for 15 minutes, stirring occasionally, until the sauce thickens. If the sauce isn't thickening quickly enough for you, put a couple of spoonfuls of the sauce into 3 tbsp of flour, and stir to a paste. Cook over medium low heat for 2 minutes to remove the starchy taste from the flour, then add 2 tbsp more sauce and mix well (you want to avoid lumps from the flour). Add the entire mixture back into the pan and stir well. Let it all boil a few minutes to thicken the sauce.
If your garlic is browning too much, add it last so the other vegetables create a bed to protect it as it browns.
Serve on buns, bread, or over rice for a tasty meal!