For the Chicken Breast:
Preheat Oven to 375°
In a sauté pan, heat 1 tablespoon olive oil. When hot, sauté the chicken breasts on one side until golden brown. Turn chicken over and transfer to cookie sheet lined with a silicone baking mat and bake for 10 minutes or until inside temperature is 160°/165°.
Make the Sauce:
In a reduction sauce pan, heat the butter and olive oil. When hot add the shallots and cook until light golden brown. Add the mushrooms and salt and pepper and cook for a few minutes (this could take 5 to 8 minutes) to let them release ALL their water.
Add the spinach and cook for a couple more minutes until wilted. Add the white wine and let it reduce by half or until very smooth.
Add the stock and cream, let it reduce on medium high heat for about 5 minutes to thicken. You may have to reduce the heat to medium to low heat.
Use a little corn starch slurry to thicken to the right consistency if needed it!
Add more butter at the end of the heat!