1For the biscuit streusel.
Combine 2 cups flour together with baking powder. Cut one stick of cold butter into pieces and work it into the flour mixture with your fingers until it resembles cornmeal. Stir in parmesan and garlic powder. Stir in cream. Line a baking sheet with parchment paper and scatter the biscuit mixture on the parchment. Bake at 375 degree until lightly browned about 12 minutes. Remove from oven and set aside.
2Place a pot of boiling salted water on stove and cook squash and potatoes until tender adding the peas the last couple of minutes. Drain and set aside.
3Place olive oil in large Dutch oven and cook chicken until no longer pink. Remove chicken from pan and set aside.
4Place onions and garlic in the pan and saute for 3 minutes. Add the mushrooms and saute another 3 minutes. Deglaze with 1/4 cup wine and let almost all evaporate.
5Add 1/2 stick of butter to pan and let melt. Stir in 6 tbsp. of flour stirring to make a roux. Slowly pour in chicken stock and remaining wine. Add rosemary and thyme. Cook until thickened.
6Add the chicken back to the pan and add the squash,potato and pea mixture. cook until warmed taste and season according to your preference.
7Pour filling into pie crust. Sprinkle streusel on top and place in 375 degree oven for about 15 minutes until crust and topping is browned.
I have also made this recipe and served it in individual ramkins. Just spoon the filling into ramkins and when making the topping form into biscuits the size of the top of the ramkin. Bake the ramkins the same.