Preheat oven to 350º F. Grease 9x13" casserole.
Combine cream and broth and bring to boil. Stir in grits; cover and cook, stirring often, until grits are thickened.

While grits simmer, cook frozen greens in microwave until tender. Drain well and squeeze out all remaining liquid. Add butter, pepper and parmesan to grits, and stir until butter melts. Stir in cooked greens and pour into casserole. Top with more cheese and bacon.

Serve either at room temperature, or warm in oven until top is brown, about 40 minutes.