Creating this Mushroom Pot Pie with Scallion Drop Biscuits can be straightforward if you follow these simple steps:

For the Mushroom Filling

1. Sauté the Vegetables: In a large skillet, heat the olive oil over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes.
2. Add Garlic and Mushrooms: Stir in the minced garlic and sliced mushrooms. Cook for another 5-7 minutes until the mushrooms are soft and releasing moisture.
3. Incorporate Carrots and Celery: Add the diced carrots and celery, cooking for about 5 minutes. Stir in dried thyme and fresh parsley for flavor.
4. Create the Sauce: Sprinkle the flour over the vegetables, stirring to coat. Gradually add the vegetable broth and heavy cream, whisking until the mixture thickens. Season with salt and pepper to taste.
5. Simmer: Allow the filling to simmer for about 10 minutes, until thickened. Remove from heat and let it cool slightly.

For the Scallion Drop Biscuits

6. Preheat Oven: Preheat your oven to 425°F (220°C).
7. Mix Dry Ingredients: In a mixing bowl, whisk together the flour, baking powder, and salt.
8. Cut in the Butter: Add the cold butter and mix using a fork or pastry cutter until it resembles coarse crumbs.
9. Add Milk and Scallions: Pour in the milk and add the chopped scallions. Stir until just combined; do not overmix.
10. Drop Biscuit Dough: Using a spoon, drop rounded tablespoons of the biscuit dough onto a lined baking sheet.

Assemble and Bake

11. Fill the Pie Dish: Spoon the mushroom filling into a pie dish or baking dish.
12. Top with Biscuits: Place the drop biscuits evenly over the top of the filling.
13. Bake: Bake in the preheated oven for 25-30 minutes, or until the biscuits are golden brown.

Once the Mushroom Pot Pie is done, allow it to cool slightly before serving. The aroma will fill your kitchen, ensuring everyone is eager to dig in!