Bring a large pot of very salted water to a rolling boil. Add broccoli rabe, stir, and let cook for 30 seconds. Remove with tongues and quickly transfer to an ice bath until completely cooled.Pat dry with paper towels.

In a large skillet or dutch oven heat the olive oil. Add the broccoli rase and sauté for 2 minutes. Add the garlic, a pinch of salt and pepper, and cook for another 3 minutes, or until broccoli has softened slightly. Remove from pan and transfer to a clean plate.

On one slice of bread layer 1/4 of the broccoli rabe, peppers, and cheese. Top with an additional slice of bread, then carefully but liberally butter both outside sides.

Heat a large skillet over a medium flame. Once hot add the sandwich and grill on each side for 2-3 minutes, or until the bread is golden and the cheese is bubbling. Repeat until all the sandwiches are made, and serve at once.