Creating your own Mushroom Shepherd’s Pie is quite simple if you follow these straightforward steps:

1. Preheat Oven: Preheat your oven to 400°F (200°C).
2. Sauté Aromatics: In a large skillet, heat the olive oil over medium heat. Add the diced onion and garlic, sautéing until translucent, about 5 minutes.
3. Cook Mushrooms: Add the chopped mushrooms to the skillet. Cook until they release their moisture and become tender, approximately 5-7 minutes.
4. Add Vegetables: Stir in the diced carrots and peas, cooking for an additional 5 minutes until heated through.
5. Season: Add the tomato paste, soy sauce, thyme, rosemary, salt, and pepper. Mix well to combine all ingredients.
6. Thicken Mixture: Sprinkle the flour over the mixture, stirring to combine. Cook for another minute to eliminate the raw flour taste.
7. Add Broth and Milk: Gradually pour in the vegetable broth and milk, stirring continuously until the mixture thickens. Allow it to simmer for a few minutes.
8. Transfer to Baking Dish: Pour the mushroom mixture into a baking dish, spreading it evenly.
9. Top with Mashed Potatoes: Spoon the prepared mashed potatoes over the mushroom filling, smoothing it out with a spatula.
10. Add Cheese (Optional): If desired, sprinkle shredded cheese on top of the mashed potatoes for added flavor.
11. Bake: Place the baking dish in the preheated oven and bake for 30-40 minutes, or until the top is golden and bubbly.
12. Cool Before Serving: Remove from the oven and allow to cool for about 10-15 minutes before serving.

By following these steps, you’ll create a delicious Mushroom Shepherd’s Pie that’s sure to impress everyone at your table!