spring panzanella

Name: spring panzanella
Cuisine: European, Italian, Mediterranean
Ingredients: For the croutons:; 1/4 cup olive oil; 2 cloves garlic, finely chopped; 6 cups day-old bread, crust removed, cubed; 6 tablespoons finely grated Parmesan, plus more for garnish; Salt and freshly ground black pepper; For the vinaigrette:; Half a red onion, finely diced; 2 to 2 1/2 tablespoons champagne or white wine vinegar; Juice of half a lemon; 1/2 teaspoon Dijon mustard; For the salad:; 4 large leeks; 2 teaspoons salt; 1 pound asparagus; 1 19-ounce can of white beans, rinsed and drained or 1 1/2 cups cooked white beans