Heat a large non-stick saucepan over medium low heat. Butter pan and toast one (or both side if preferred) of each slice of bread until toasted and golden. Remove bread from heat and dress bread with mayonnaise, whipped cream cheese or mustard as desired, top one slice with lettuce and set aside.
Return pan to heat, butter pan again and layer turkey slices into pan. Cook turkey until lightly golden on bottom (only takes about 1 minute), then flip turkey using a spatula. Remove from heat and top turkey with shredded Mozzarella cheese, sprinkle with ham, then layer with avocado slices, followed by tomato slices, then sprinkle with with Italian seasoning. Return to heat and cook until cheese has melted and bottom of turkey is lightly golden. Using the spatula, carefully lift out layered sandwich filling and lay on top of sliced bread containing lettuce. Top with remaining slice. Serve immediately (you may want to cut it in half to be able to eat this one =).