Coat a large skillet with non-stick spray and the olive oil. Turn the pan on to medium heat and add the Brats to the pan. Cook them, turning them so they don't burn, until they're cooked through.
Save the grease in the pan.
Cut the brats into 1/4-inch thick slices, and then quarter them and set them aside.
Add the diced onions, garlic, and bell pepper in brat grease and saute them until the onions are translucent.
Divide the flank steak/brisket into four parts and add it one portion at a time to the leftover brat grease, searing it until it is browned on all sides. Brown all four batches separately, so they brown evenly.
Add the meats, beans, onion, garlic, pepper, chili powder, marjoram, paprika, thyme, and tarragon to a 5-quart crockpot and mix well. Add stewed tomatoes and salsa. Mix well. Add brown sugar. Mix well.
Cook the mixture in the crockpot on low for 10 to 12 hours. If you want thicker chilli, to be used as a dip, take the lid off and cook until enough liquid evaporates.
Top with shredded cheese, chives, onions, sour cream or any other of your favorites.