White Bean and Tuna Salad with Radicchio and Parsley Vinaigrette

Name: White Bean and Tuna Salad with Radicchio and Parsley Vinaigrette
Ingredients: 2 cups (packed) flat-leaf parsley (leaves and stems); 1 /2 cup olive oil; 3 tablespoons fresh lemon juice; 1 /2 tablespoon Champagne vinegar; 1 garlic clove, crushed; Kosher salt and freshly ground black pepper; 1 medium head of radicchio, cored, leaves coarsely torn; 2 15-ounce cans cannellini (white kidney) beans, rinsed, drained; 2 celery stalks, peeled, sliced thinly on an extreme diagonal; 1 cup drained olive oil–packed tuna in a jar or good-quality canned tuna, broken into large pieces; Flat-leaf parsley sprigs (for garnish)