While potatoes are cooking, preheat oven to 425 degrees F (220 C) and lightly grease a 9x13-inch (or similar size) baking dish (or more baking dishes, as needed, if altering batch size).
*3 large sweet potatoes is equal to ~5 small sweet potatoes.
*You can sub 1 tsp dried thyme per 2 tsp fresh thyme.
*Nutrition information is a rough estimate calculated with 3 Tbsp of oil total, and without the baked mushrooms or optional maple syrup.
*Recipe adapted from my 1-Hour Vegan Shepherd's Pie.