How to Make It
In a large skillet, heat 1 tablespoon of the olive oil. Add the celery, season with salt and cook over high heat, stirring a few times, until it begins to brown, about 4 minutes. Add the water, vermouth and bay leaf. Cover and cook over moderately low heat, stirring occasionally, until the celery is tender, about 20 minutes.
Drain the celery and let cool slightly, then slice the ribs on the diagonal 1/8 inch thick. Transfer to a bowl. Stir in the chiles and their pickling liquid and the remaining 4 tablespoons of olive oil. Season the relish with salt and pepper.
Preheat the oven to 450°. Place the bread directly on 2 oven racks and bake until lightly toasted, 3 minutes. While still warm, rub the garlic on one side of each slice. Lay the toast on a surface, garlic-rubbed side up. Top half of the slices with the roast beef and the celery-chile relish. Close the sandwiches, cut them in half and serve.