Put bread, brushed with 2 tablespoons oil and seasoned with salt and pepper, on a baking sheet. Broil 2 minutes per side. Rub with cut garlic.
Cook broccoli rabe in boiling salted water until tender, 5 to 6 minutes. Drain well. Wipe pot.
Cook garlic and pepper flakes in remaining 1/4 cup oil over medium heat, stirring, 2 minutes. Add broccoli rabe, 3 tablespoons water, and salt and cook, covered, stirring occasionally, 2 minutes.
