Buckwheat and Roasted Vegetable Tabbouleh Salad

Name: Buckwheat and Roasted Vegetable Tabbouleh Salad
Ingredients: 1 cup cooked hulled buckwheat (see Notes); ½ butternut squash, diced and roasted, about 1½ cups (see Notes); 3 yellow beets, peeled, roasted, and diced (see Notes); 4 stalks asparagus, blanched and roughly chopped (optional); ½ cup finely chopped fresh parsley; 1/3 cup lemon juice; 3 scallions chopped; ¼ cup olive oil; 2 tablespoons chopped fresh tarragon; 1 tablespoon lemon zest; 1 tablespoon chopped fresh mint; 1 tablespoon maple syrup; Salt and pepper