Take out frozen biscuits before you start cooking to let them thaw. Cut them into quarters, so that you have 8 pieces of biscuit.
In a deep skillet or pot, sautee the garlic in the butter over medium heat, and add the mushrooms, stirring occasionally. Keep over medium heat until all of the liquid from the mushrooms has evaporated.
While the mushrooms are on the stove, place the frozen biscuit pieces in a plastic bag full of flour and coat, to keep them from sticking to your hands. Using your palms, roll the biscuit quarters into balls. Set aside.
Add the frozen vegetables to the mushrooms and garlic. Cook until the excess water has evaporated and the frozen vegetables are cooked.
Add the mushroom gravy, stirring to coat all of the vegetables. Thin with vegetable broth as needed.
Turn the heat down a little bit. Drop the rolled biscuit pieces into the mushroom "stew" a few inches appart and cover with a lid. Simmer until the biscuits are puffy and cooked though.