Make the crepe batter: Whisk 0.8 cups all-purpose flour (crepes), 1 pinch salt, to taste (crepes), and 0.5 teaspoons baking powder together. Gradually pour in 1.3 cups whole milk (crepes), whisking until smooth and thin. Rest for 5 minutes.
Cook the crepes: Heat a lightly greased non-stick skillet over medium heat. Pour a small ladleful of batter and swirl to spread thin. Cook 1–1m 30s
until edges set, flip, cook 30 seconds more. Repeat and stack.
Make the white sauce: Melt 1 tablespoons butter (white sauce) in a small saucepan. Stir in 1 tablespoons all-purpose flour (white sauce) and cook 5 minutes
. Slowly whisk in 1 cups whole milk (white sauce) until smooth. Add 1 teaspoons Italian seasoning (white sauce) and 1 pinch salt, to taste (white sauce). Stir until thickened. Set aside.
Cook the filling: Heat 1 tablespoons oil (filling) in a skillet over medium-high. Sauté 1 tablespoons garlic, chopped for 8 minutes
. Add 2 cups cremini or button mushrooms, sliced and cook 4–5 minutes until browned. Season with 1 pinch salt & red pepper flakes, to taste and 1 tablespoons Italian seasoning (filling). Stir in 2 cups fresh spinach, chopped and wilt for 1–2 minutes. Add 0.3 cups heavy cream and 0.3 cups shredded mozzarella or melting cheese, stir and cook 1 minute.
Fill and serve: Lay each crepe flat, spoon filling down the center, and fold or roll. Arrange on a plate, spoon warm white sauce over the top, and finish with 0.3 cups extra grated cheese, for topping. Serve immediately.