In a small saucepan, melt butter and sauté onion and garlic until soft. Add spices and milk, and bring to a simmer. Pour over the breadcrumbs and let soak for 15 minutes.
Preheat oven to 400F.
In a large bowl, knead together the breadcrumb paste, ground beef, and egg. Form into small meatballs, place on a baking tray, and bake for 15-20 minutes, until fully cooked.
While they bake, whisk together butter and flour for the sauce. Pour in the chicken stock, milk, and yogurt. Season with salt and pepper.
Add cooked meatballs to the sauce and simmer for 10 minutes. Serve immediately over egg noodles, rice, or quinoa.