In a large skillet, heat 2 tablespoons of the olive oil over medium heat until shimmering Add the garlic and chili and cook until fragrant, 30 seconds to 1 minute. Add the broccoli rabe and a pinch of salt and sauté for 2 to 3 minutes. Add about 1/2 cup water, cover, and steam until the stalks are tender, the leaves have wilted, and most of the water has cooked off, 2 to 3 minutes.

Move the broccoli rabe over to one side of the pan and add the sausage meat to the empty side. Cook, stirring to break the sausage up into crumbles, until the sausage is browned and cooked through, 4 to 5 minutes. Fish out and discard the garlic when ready to serve.

In a large skillet, heat the remaining 2 tablespoons olive oil over medium heat. Add the bread cut-side down and pan-grill until golden brown and crisp, 3 to 4 minutes. Turn the bread over and add a layer of provolone. Cover and cook until the cheese is melted.

Serve each toast topped with a generous portion of broccoli rabe and sausage.