8 (1/2 Ounce) Slices Sriracha-Flavored Gouda Cheese (such As Roth(R))
3 Slices Crisp-Cooked Bacon, Halved
Preheat the oven to 450 degrees F (230 degrees C). Toss tots with oil on a baking sheet.
Bake, turning over halfway through, until browned, about 24 minutes.
Meanwhile, heat 1 tablespoon butter in a large skillet over medium heat. Stir in spinach, salt, and pepper; cook until spinach is wilted and lightly browned in places, about 5 minutes. Transfer to a plate and wipe skillet clean.
Spread 2 bread slices with mayonnaise, then top each with 2 slices cheese and 1/2 of the bacon and spinach, then top each sandwich with remaining cheese and bread.
Melt remaining 1 tablespoon butter in skillet over medium heat. Add sandwiches; cook, lightly pressing with a spatula, until cheese is melted and bread is golden brown, about 3 minutes per side.