Toss vegetables with flour in a large bowl. Add turkey, soup, thyme and pepper; mix well.
Spread half of mixture into a 13x9 inch glass baking dish. Arrange cheese over mixture; top with remaining turkey mixture. Cover with foil. Bake in a 375° oven for 15 minutes.
Separate biscuits; cut each into quarters. Uncover casserole arrange biscuit dough evenly over top of casserole. Return to oven and bake 18 minutes more or until biscuits re deep golden-brown and sauce is bubbly.