Ingredients

  • 1 head of garlic
  • 4 tablespoons plus 3/4 cup olive oil
  • 1/4 cup finely chopped shallots
  • 4 tablespoons balsamic vinegar
  • 2 tablespoons chopped fresh thyme
  • 2 large red onions, sliced into 1/4-inch-thick rings, separated
  • 2 tablespoons (1/4 stick) butter
  • 6 garlic cloves, chopped
  • 2 cups 1/2-inch cubes day-old sourdough bread
  • 1 teaspoon chopped fresh rosemary
  • 8 cups (packed) arugula leaves (about 10 ounces)
  • 1 cup (packed) grated smoked mozzarella cheese (about 4 ounces)

Method

  • Preheat oven to 350F.
  • Place garlic in small baking dish.
  • Drizzle with 2 tablespoons oil.
  • Cover dish tightly with foil; bake until garlic is tender, about 50 minutes.
  • Cool.
  • Squeeze roasted garlic from skins into medium bowl.
  • Mash with fork.
  • Add 3/4 cup oil, shallots, 3 tablespoons vinegar, and thyme.
  • Whisk to blend well.
  • Season with salt and pepper.
  • Increase oven temperature to 375F.
  • Oil large rimmed baking sheet.
  • Arrange onion rings on sheet.
  • Sprinkle with salt and pepper.
  • Drizzle with remaining 2 tablespoons oil; toss to coat.
  • Roast until tender and brown, stirring occasionally, about 30 minutes.
  • Drizzle with remaining 1 tablespoon vinegar; toss to coat.
  • Add onions to vinaigrette in bowl.
  • Maintain oven temperature.
  • Melt butter in heavy medium ovenproof skillet over medium heat.
  • Add chopped garlic and saute 30 seconds.
  • Add bread cubes and rosemary and toss to combine.
  • Transfer to oven and bake until croutons are golden and crisp, about 10 minutes.
  • Place arugula in large bowl.
  • Add cheese and toss to combine.
  • Transfer vinaigrette to medium saucepan.
  • Stir over medium-low heat until hot.
  • Pour hot dressing over arugula salad and toss to combine.
  • Season to taste with salt and pepper.
  • Top with croutons and serve.