Preheat oven to 375 degrees F and coat an 8x8-inch baking dish with nonstick cooking spray.
Whisk mayonnaise, flour, bouillon, and pepper together in a saucepan. Slowly pour in the milk while whisking, and turn on the heat to medium. When the sauce boils, cook for 2 more minutes to thicken.
Stir in the turkey and vegetables and heat through. Pour into prepared baking dish.
Pop open the crescent roll tubes. Rip the rolls apart into two big rectangles, then pinch the dough together into one relatively smooth rectangle and place on the baking dish.
Bake for 15 to 20 minutes until crescent rolls have baked through and are light brown.