Asparagus and Feta with Mint

Name: Asparagus and Feta with Mint
Ingredients: salt; 1/2 medium red onion, sliced thinly; 1 tablespoon red wine vinegar; 1 1/2 pounds asparagus, woody ends removed ((about 2 bunches)); 4 cups torn croutons; 24 large mint leaves; 3 ounces feta cheese; Double Batch Red Wine Vinaigrette ((See recipe below)); 1 pound loaf day -old country or sourdough bread; 1/3 cup extra-virgin olive oil; 1 tablespoon shallot, finely sliced; 2 tablespoons red wine vinegar; 6 tablespoons extra-virgin olive oil; salt; fresh ground pepper