1. Meanwhile, preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).
2. Add the flour and mix to coat the vegetables. Add the cooking cream or half-and-half, wine, cheese, and seasoning. Stir for a minute or two until cheese is melted and all ingredients are well combined. Add a few spoonfuls of this mixture to the spinach filling and mix well.
3. Place a spoon of spinach filling mixture on each crepe and roll up. Put blintzes in a baking dish, preferably Pyrex, lined with parchment paper. They can be very close together. Spoon remaining sauce over blintzes.
4. Spray a large piece of aluminum foil with cooking spray, and cover baking dish (sprayed side down, so it won’t stick).
5. Bake for 20 minutes covered, then 10 minutes uncovered. Garnish with chopped chives, if desired.
If you would like a thinner, more pourable mushroom sauce, you can add 1/2 cup of milk to the mixture after removing some of the sauce for the spinach filling. I prefer it thick as it is, though.