Preheat oven to 350 degrees
Combine meatball ingredients, and roll into 2 inch balls. Arrange on a baking sheet and bake 30 minutes, until cooked through.
In a deep skillet, saute` butter, garlic, shallot, mushrooms, and whole rosemary sprigs on medium high heat until onions are caramelized.
Add white wine and beef broth, and simmer for 15 minutes. Reduce heat to medium low,
Whisk cornstarch with a couple tablespoons of water, then whisk into the beef broth and wine mixture. Simmer for another 3 mintues until thickend.
Reduce heat to low, and whisk in the cream.
Add meatballs to the sauce, turn to coat, and simmer until all of the meatballs are cooked through, then remove from the heat.
Serve meatballs and sauce on buttered pasta or mashed potatoes.