Mix 1/3 cup mayonnaise, sour cream, 1 tablespoon pesto, hot sauce, salt, and pepper in a bowl to make dipping sauce. Place in the refrigerator.
Combine 1/4 cup mayonnaise, egg, 2 tablespoons pesto, and garlic in a large bowl. Stir in bread crumbs and red onion. Mix in chicken until thoroughly combined. Form mixture into balls; press into 1/2-inch cakes.
Heat oil in a nonstick skillet over medium heat. Add chicken cakes to the oil in a single layer; cook until browned, about 3 minutes per side. Transfer to a platter lined with paper towels. Repeat with remaining chicken cakes.
Substitute full-fat plain Greek yogurt for the sour cream if desired.
This is a very flexible recipe. You can skip the pesto and use your own sauce mixture. I've used seasoned tomato paste (in a tube) in place of the pesto, added cheese, and served with marinara sauce for a chicken parm cake.
Triple the recipe and it makes a lot of hors d'oeuvres for a larger crowd. You can prep them, freeze them, and thaw a day ahead of the event as well.
Per Serving: 309 calories;22.4 g fat;
10.9 g carbohydrates;
15.6 g protein;
73 mg cholesterol;
251 mg sodium.