1. Grill sausage according to package directions. Cut into 1/4″ slices.
2. Slice Ciabatta rolls in half and add butter to one side of the sliced roll. Place butter-side-down and assemble each sandwich beginning with 2 slices cheddar cheese, handful of spinach, sliced tomatoes, cooked sausage slices, 2 slices cheddar cheese and top with the remaining half of Ciabatta roll. Add butter to top of roll.
3. Heat sandwich in a skillet, grill, panini press or sandwich press. Apply pressure for approximately 5 minutes. Turn and apply pressure to other side for an additional 3 minutes or until heated through.
4. To make sauce combine mayonnaise, mustard, and Worcestershire sauce. Mix well.