This dairy-free mashed potato casserole recipe was originally shared with us by a reader several years ago. They pronounced it a dinner time favorite, but we think it could also be great for the holidays.
The recipe is much lower in fat than similar dishes because it’s made without any butter or oil in the mashed potatoes. In fact, the only oil used is to saute the filling. If you prefer some richness, you can add a little olive oil or buttery spread to the potatoes before baking. But you might want to try it without first!
Special Diet Notes: Mashed Potato Casserole
By ingredients, this recipe is dairy-free / non-dairy, gluten-free, grain-free, nut-free, peanut-free, soy-free, and vegetarian.
- For egg-free and vegan options, see our Egg Substitute Guide.
- 2½ pounds potatoes, unpeeled
- Salt, as needed
- 3 tablespoons olive oil
- 2 medium onions, chopped
- 8 ounces small mushrooms, quartered
- 1 garlic clove, minced
- Black pepper, as needed
- ¼ cup vegetable broth, chicken broth, or unsweetened dairy-free milk beverage
- 2 large eggs, beaten
- ½ teaspoon paprika (optional)
- Put the potatoes in a large pot, cover with cold water, and add a pinch of salt. Bring the water to a boil, reduce the heat to low, and simmer for 35 minutes, or until very tender. Drain and let cool.
- Preheat your oven to 350°F and grease a 6- or 7-cup casserole dish.
- Heat the oil in a large skillet over medium heat. Add the onion and saute until light golden, about 5 minutes. Add the mushrooms and saute over medium-high heat for 5 minutes. Add the garlic and saute for 2 more minutes or until the mushrooms are browned. Season with salt and pepper to taste.
- Peel the potatoes, if desired, and put them in a mixing bowl. Beat with a mixer on low speed until coarsely mashed. Beat in the broth or milk beverage. Beat in the eggs, just until blended.
- Stir in ½ cup of the reserved mushroom mixture. Add ¾ teaspoon salt and ½ teaspoon black pepper, or to taste.
- Spread half of potato mixture into your prepared casserole dish. Top with the remaining mushroom mixture, and then with remaining potato mixture. Smooth the top and sprinkle with paprika, if desired.
- Bake the casserole uncovered for 50 minutes, or until top is firm.