Preheat your grill, griddle, or skillet to medium-high heat until hot enough to caramelize the bologna.
Spread a thin layer of mayonnaise on both sides of each bologna slice, then season generously.
Place the bologna over direct heat and cook for about 1 minute per side, flipping as needed, until caramelized and slightly crispy around the edges.
While the bologna cooks, spread the remaining mayonnaise on the cut sides of the buns.
Toast the buns over indirect heat until golden brown.
Assemble the sandwiches by placing the bologna on the bottom buns. Top with shredded lettuce and sliced tomato, then season lightly with salt and pepper.