This salad offers a pleasing blend of flavors: the mildly bitter sensation of the endive and the radicchio, the saltiness imparted by the anchovies, and the sharpness of the black pepper and the red-wine vinegar.
In a small bowl, submerge anchovies in 1/4 cup red-wine vinegar. Let soak for 30 minutes; drain, and discard liquid.
Place anchovies and garlic on a cutting board. Sprinkle with salt, and mince into a paste; place in a medium bowl. Whisk in remaining tablespoon vinegar, olive oil, and pepper. Set aside.
Arrange sliced endives and Treviso radicchio leaves on four salad plates. Drizzle anchovy mixture over each. Serve immediately.
Soaking anchovies in red-wine vinegar gives them a wonderful pickled flavor.