Gently pat tofu dry with paper towels. Slice into 1/8-inch thick slices right onto dry paper towels. Generously season one side with 1 tablespoon steak seasoning.
Heat oil in a nonstick skillet over medium heat. Carefully slip tofu, seasoned-side down, into the pan using a small spatula. Season the top side with the remaining steak seasoning.
Cook tofu until dried and lightly browned, 4 to 5 minutes per side. Drain on paper towels.
Spread mayonnaise over each slice of bread. Divide tofu, tomatoes, and lettuce over 4 slices; cover with the tops.
