Preheat oven to 350 degrees F. Prep mashed potatoes, if needed.
5-6 cups mashed potatoes
Warm olive oil in a deep oven-safe skillet over medium-high heat. Add onion and carrots. Cook 2-3 minutes, until beginning to soften. Add mushrooms, faux meat crumbles, garlic, and rosemary. Stir well and cook 5-6 minutes, stirring often.
Stir in tomato paste, flour, and Worcestershire sauce, followed by red wine. Cook 1-2 minutes, then slowly add the broth, stirring and scraping the bottom of the pan. Reduce heat to medium-low and simmer 3-4 minutes, until the sauce is slightly thickened. Season with salt and pepper to taste. (I add 1 teaspoon salt and 1/8 teaspoon pepper.)
2 Tablespoons tomato paste, 2 Tablespoons all-purpose flour, 2 teaspoons Worcestershire sauce, 1/2 cup red wine, 1 and 1/2 cups vegetable broth, salt and black pepper
Remove from heat, stir in peas and parsley, and spread the mixture out evenly across the bottom of the skillet.
Scoop the warm mashed potatoes into dollops on top of the veggie mixture, and use a spatula to spread them into a roughly even layer. Bake for 15 minutes, then set the oven to broil for 1-2 minutes to brown the top. Remove and dig in.
Notes
Mashed potatoes. You can use any mashed potatoes you like for this recipe -- leftovers, homemade, or from a box! Just be sure they are warm before trying to spread them out on top.
Make ahead. You can fully prep this shepherd’s pie -- right up to spreading the mashed potatoes on top -- the night before or the morning of the day you want to eat. Store it covered in the fridge, then bake for 25-30 minutes.
Store leftovers. This makes a fairly large dish, so you can feed a crowd or enjoy the extra throughout the week. It keeps well tightly-covered in the fridge for at least 4 days and is easy to reheat in the microwave.
Freeze. If planning to freeze, transfer the vegetable mixture to a metal or foil baking dish, add the mashed potato topping, and bake as directed. Let it cool all the way to room temperature, wrap tightly with foil, and freeze for up to 4 months. The shepherd's pie can be baked straight from the freezer to reheat -- it will take at least 50-60 minutes at 350ºF. Individual portions can be frozen the same way.