Set an oven rack about 6 inches from the heat source and preheat the oven's broiler or set a toaster oven to broil. Place rolls cut-sides up in a single layer on a baking sheet.
Toast in the preheated broiler until lightly brown, 1 to 3 minutes.
Slice luncheon meat lengthwise into nine ¼-inch thick slices.
Heat a cast-iron or nonstick skillet over medium-high heat. Cook meat slices until lightly browned, about 1 minute per side; transfer to toasted roll bottoms.
Cook pineapple rings in the same skillet until lightly browned, 1 ½ to 2 minutes per side. Cut each pineapple ring into 3 pieces; set aside.
Divide and spread Sriracha among meat slices; top with 1 pineapple piece, drizzle with lime juice, and cover with roll tops.
