Halve the brioche buns and quickly toast in a large dry non-stick frying pan on a medium-high heat, then put aside. Squeeze the sausages out of their skins into a bowl, then divide into 4 and with wet hands flatten out into 1cm-thick patties. Drizzle 1 tablespoon of olive oil into the pan, add the patties and cook for 2 minutes on each side, or until golden and cooked through, then remove to a plate. Meanwhile, drain the peppers and cut the Manchego into 4 slices (discarding any rind). Carefully stuff the peppers with the Manchego slices, then cook in the pan until starting to ooze, turning occasionally.
To serve, spread 1 teaspoon of olive tapenade over the base of each bun. Place a sausage patty on each one, then top with the Manchego-stuffed peppers and the bun lids, and get stuck in.