How to Make It
In a large nonstick skillet, heat the olive oil. Add the bratwurst and cook over moderately high heat, turning once, until browned and sizzling, about 5 minutes.
Spread mayonnaise on each slice of toast. Arrange the tomato and cucumber slices on 4 slices of the toast and season with salt and pepper. Top with the hot bratwurst and lettuce. Close the sandwiches and serve.