Spiced Burgers With Cucumber Yogurt

Name: Spiced Burgers With Cucumber Yogurt
Ingredients: 1/2 seedless cucumber, peeled and finely chopped; 1/2 cup low-fat plain Greek yogurt; 1 tablespoon chopped fresh cilantro; Kosher salt and freshly ground pepper; 1 1/4 pounds 90 percent lean ground beef; 1/4 cup finely chopped red onion; 1 clove garlic, finely grated; 1 1/2 teaspoons red or yellow curry powder; 1 tablespoon extra-virgin olive oil; 4 hamburger buns, split, toasted; Sweet potato chips, for serving (optional); Pickled okra or other pickled vegetables, for serving (optional)