Direction

1. large skillet over medium-high; add garlic, and cook, stirring often, until garlic is fragrant but not browned, about 30 seconds. Add broccoli rabe and broccoli florets; cook, stirring often, until just tender and vegetable mixture cooks down to half its volume (about 3 1/2 cups), about 4 minutes. Add crushed red pepper (if using), black pepper, and salt. Transfer to a large bowl, and set aside. Wipe skillet clean.
2. Drain and discard any liquid from cooked greens. Add mayonnaise, Dijon, and lemon juice to greens; stir well. Season with black pepper and salt to taste. Set aside.
3. Melt remaining 2 tablespoons butter in reserved skillet over medium. Add bread, and toast until golden brown on bottom, about 2 minutes. Flip bread, and top each slice evenly with reserved greens. Arrange 2 cheese slices on each bread slice. Transfer skillet to oven, and broil until cheese melts and is bubbling, 2 to 4 minutes. Garnish with black pepper, and serve immediately.