Lemony Escarole Salad with Peaches and Feta

Name: Lemony Escarole Salad with Peaches and Feta
Ingredients: 1/4 cup plus 1 tablespoon extra-virgin olive oil; 3/4 teaspoon finely grated lemon zest; 1/4 cup fresh lemon juice; 1 garlic clove, finely grated; Pinch of sugar; Kosher salt; Freshly ground black pepper; 2 medium heads of escarole, inner light green and white leaves only, torn into bite-size pieces; 2 large peaches—halved, pitted and thinly sliced; 2 cups yellow cherry tomatoes, halved; 2 Persian cucumbers, thinly sliced crosswise; 1/2 small red onion, halved and thinly sliced; 6 ounces feta cheese, crumbled (about 1 1/2 cups); Ground sumac (see Note) and/or dried oregano, for garnish (optional)