Gravy: Melt margarine in a large stock pot.
Add ½ cup 1 Tbsp (about 2½ oz) flour. Cook uncovered over medium heat for 8-10 minutes. Stir frequently until golden brown. Set remaining flour aside for step 8. Recommended to cook in batches of 25.
Add mushrooms, tomatoes, onion powder, ½ tsp pepper, and ½ tsp salt. Cook for 2 minutes.
Slowly add chicken stock, and bring to a boil. Reduce heat to medium.
Add dijon mustard, stirring constantly until thickened. Set aside for step 14.
Critical Control Point: Heat to 165 °F or higher for at least 15 seconds.
Critical Control Point: Hold for hot service at 140 °F or higher.
Combine remaining flour, salt, and pepper in a small bowl. Stir well.
Pour 1¾ cups (about 4 oz) seasoned flour, onions, ground turkey, and ground beef into a commercial mixer (batch as needed). Using a paddle attachment, mix on low speed for 2 minutes. DO NOT OVERMIX.
Using a No. 10 scoop, portion ¼ cup 3 Tbsp (about 4 oz) meat patties onto a sheet pan (18” x 26” x 1”). Flatten 25 meat patties into an oval shape in each pan. Sprinkle ½ tsp remaining seasoned flour evenly over each meat patty.For 25 servings, use 1 pan.For 50 servings, use 2 pans. Bake:Conventional oven: 350 °F for 25-30 minutes.Convection oven: 300 °F for 15-25 minutes. Critical Control Point: Heat to 165 °F or higher for at least 15 seconds.
Transfer steaks to a steam table pan (12” x 20” x 2½”).For 25 servings, use 1 pan.For 50 servings, use 2 pans. Pour 1 qt (about 1 lb 11 oz) gravy over each pan.
Critical Control Point: Hold for hot service at 140 °F or higher.
Serve one steak.