| Line a sheet pan with parchment for the shaped meatballs |
| 3/4 cup plain dry bread crumbs | soak 5 min | mix gently | shape into 1 1/4-in balls | brown in batches 8 to 10 min, set aside | return meatballs, simmer low 5 to 10 min until 160°F inside |
| 1/3 cup milk |
| 1/2 cup onion, finely chopped or grated |
| 1 large egg |
| 1 lb ground beef |
| 1/2 lb ground pork |
| 1 tsp table salt |
| 1/2 tsp black pepper |
| 1/4 tsp ground nutmeg |
| 1/4 tsp ground allspice |
| 2 Tbsp butter |
| 3 Tbsp butter | cook in the pan drippings 2 min | whisk in, simmer until thick | stir in off heat |
| 3 Tbsp all-purpose flour |
| 2 cups beef broth |
| 1 tsp Worcestershire sauce |
| 1/2 cup full-fat sour cream |