Shape the chilled falafel mixture into 4 patties (the mixture will be loose). Spread the panko on a sheet of parchment paper and dip the patties into the crumbs to coat on all sides.
In a large nonstick skillet over medium, heat 1 1/2 tablespoons of the remaining oil. Add the falafel patties and cook until crisp and golden on one side, about 3 minutes. Add the remaining 1 1/2 tablespoons of oil and turn the patties; cook for another 3 minutes, or until crisp and golden.
To serve, transfer the patties to serving plates and top with yogurt sauce.
Nutrition information per serving: 620 calories; 200 calories from fat (32 percent of total calories); 22 g fat (3.5 g saturated; 0 g trans fats); 45 mg cholesterol; 76 g carbohydrate; 21 g fiber; 30 g sugar; 34 g protein; 670 mg sodium.
EDITOR'S NOTE: Sara Moulton was executive chef at Gourmet magazine for nearly 25 years, and spent a decade hosting several Food Network shows. She currently stars in public television's "Sara's Weeknight Meals" and has written three cookbooks, including "Sara Moulton's Everyday Family Dinners."