Split Italian sausage into four equal parts and form a rectangular pattie out of each part.
Slice the peppers and onions thinly, about 2 inches long.
Make the Sauce
Mix the mayo, mustards, garlic, Worcestershire sauce, and minced garlic together in a small bowl. Season with Kosher salt and pepper to taste.
Cook the Veggies and Sausage
Add about a tablespoon of sunflower oil to a cast iron pan. Heat to medium-high and add the peppers and onions. Cook until soft and browned. Remove from the pan.
Add the sausage patties and cook for about 4-6 minutes each side or until cooked through. Use a spatula to gently press down the patties so the entire rectangle of sausage touches the cooking surface.
If using cheese, add to the top of each patty when the patties are nearly finished and let melt. Remove from pan.
Toast the Bread
Drain excess fat from the skillet and then add about a teaspoon of Earth Balance. Let melt and then add the sliced baguettes, inside down, to the pan and toast. Flip and toast the outside slightly. Remove from pan.
Make the Sandwich
Spread mustard sauce on both slices of the baguette. Add one sausage patty to the bread and some onions and peppers. Enjoy!