In a large mixing bowl, combine 500 grams of minced meat (chicken, pork, or beef), 1 finely chopped onion, 2 minced garlic cloves, 1/4 cup breadcrumbs, 1/4 cup all-purpose flour, 1 beaten egg, salt, and pepper to taste. Mix well until all ingredients are combined.
Shape the mixture into small, round meatballs, approximately the size of a golf ball.
Heat 2 tablespoons of oil in a large frying pan over medium heat. Add the meatballs and cook for 10-12 minutes, turning occasionally, until they are browned and cooked through. Remove from the pan and set aside.
To prepare the yogurt sauce, whisk together 1 cup of curd (strained to remove excess water), 1/2 cup of finely chopped cucumber, 2 tablespoons of chopped fresh dill, 1 minced garlic clove, salt, and pepper to taste in a small bowl.
Serve the frikadeller with the yogurt sauce on the side, garnished with additional dill if desired.