Drain the oil from the tomatoes and reserve 3 tablespoons. Discard the rest. Dump the frozen meatballs, drained sun dried tomatoes and frozen spinach into the insert of a 6-quart Crock-Pot.
In a microwave-safe 8-cup glass measuring cup, combine the three tablespoons of sun dried tomato oil and the flour. Microwave for one minute. Use a fork or small whisk to stir util smooth. Microwave in two more one minute bursts, stirring each time, until the mixture is well combined and bubbly.
Add the chicken broth, tomato paste, Worcestershire sauce, garlic, Italian seasoning, salt, pepper and red pepper flakes. Whisk well.
Microwave for one more minute and whisk one final time. Pour the mixture over the meatballs and spinach. Cover and cook on HIGH power for 4 hours.
With 30 minutes remaining, stir in the gnocchi and sour cream. Be sure and separate the gnocchi if they have stuck together in the package.
Keep cooking on high for the remaining 30 minutes, until the gnocchi is cooked through. Serve dishes of the meatballs, gnocchi and sauce topped with Parmesan cheese.