Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
Warm the ribs on a baking sheet until hot.
Toast the rolls, optional.
Assemble Sandwiches: Spread mayonnaise on each slice of bread. Place the ribs on the bun, drizzle with bbq sauce. Top each with sliced onions and pickles. Place the remaining slices of bread on top to form sandwiches.
Mix the ingredients for the lemon sparkling water.
Serve barbecue rib sandwiches with carrots and ranch and lemon sparkling water.