Potatoes, Onion, Mushroom Au Gratin

Prep: 30 min Cook: 60 min Serves: 8 Cuisine: American

A rich, cheesy au gratin featuring tender potatoes, sautéed mushrooms, and sweet onions, perfect for family dinners or special occasions craving comfort and bold flavors.

Be the first to rate this recipe

Ingredients

  • 5 lb. potatoes
  • 1/2 cup butter
  • 1 lb. mushrooms
  • 1/2 cup flour
  • 1 quart milk
  • 1 cup cream or evaporated milk
  • 1 can condensed consommé
  • 1 lb. sharp cheese, grated
  • 1 tablespoon seasoned salt
  • 1/4 teaspoon pepper
  • 1 teaspoon Worcestershire sauce
  • 2 cans small white onions

Instructions

  1. Cook potatoes the night before with jackets on.
  2. Cool, peel, and cut potatoes into cubes.
  3. Heat butter in a large kettle and sauté mushrooms until brown.
  4. Stir in flour, milk, cream or evaporated milk, condensed consommé, and grated cheese.
  5. Add seasoned salt, pepper, and Worcestershire sauce.
  6. Cook, stirring until smooth and thick.
  7. Remove from heat and add the prepared potatoes and drained small white onions.
  8. Mix well, then spoon into a shallow pan or 4-quart casserole dish.
  9. Cover and refrigerate overnight.
  10. Bake at 350°F for 1 hour until bubbly and golden.

Tips & Substitutions

For an extra depth of flavor, consider adding garlic or herbs like thyme while sautéing the mushrooms. If you're short on time, pre-packaged cubed hash browns can be a great substitute for fresh potatoes. You can also use a mix of cheeses, such as Gruyère or mozzarella, for a different taste profile. This dish is perfect for potlucks or family gatherings, similar to American recipes like Aunt Bea's Favorite Pound Cake.

Serving Suggestions

Serve this rich and creamy au gratin dish alongside a simple green salad or roasted vegetables for a balanced meal. It pairs beautifully with grilled meats or a savory roast. For a comforting dessert, consider following it up with Supreme Chocolate Cheesecake to satisfy your sweet tooth.

Storage & Reheating

Store leftovers in an airtight container in the refrigerator for up to 3 days. To reheat, place in a preheated oven at 350°F for about 20-30 minutes, covering with foil to prevent drying out. If reheating individual portions, a microwave works well, but be sure to cover it to retain moisture.

Nutrition & Diet Analysis (per serving)

Each serving of Potatoes, Onion, Mushroom Au Gratin contains roughly 2015 calories, with 54g protein, 227g carbohydrates, and 99g fat. It is an excellent source of protein (109% of the Daily Value), potassium (104% of the Daily Value), and vitamin C (97% of the Daily Value). Note that it is relatively high in sodium, at 2057mg per serving (89% of the Daily Value).

2015 kcal 100% DV
Protein Fat Carbs

Macronutrients

Protein 54.5g 100% DV
Total Fat 99g 100% DV
Carbs 227.3g 83% DV
Fiber 17g 61% DV
Sugar 28.5g 57% DV

Electrolytes

Sodium 2057mg 89% DV
Potassium 4873.8mg 100% DV
Cholesterol 121.6mg 41% DV

Vitamins & Minerals

Vitamin A 422mcg 47% DV
Vitamin C 86.9mg 97% DV
Vitamin D 17mcg 85% DV
Calcium 1137.1mg 87% DV
Iron 8.2mg 45% DV
Diet fit High-protein High-fiber
Contains Milk Wheat/Gluten

Estimated from ingredients & per-serving nutrition — verify against package labels for allergies or strict diets.

* % Daily Values based on a 2,000 calorie diet (FDA 2020).

Frequently Asked Questions

Can I make this dish ahead of time?

Absolutely! In fact, refrigerating it overnight allows the flavors to meld beautifully. Just follow the recipe up to the baking step, then cover and store in the fridge. Bake it the next day as instructed for a deliciously convenient meal.

Can I use different types of cheese?

Yes, you can mix and match cheeses based on your preference. Cheddar adds sharpness, while Gruyère offers nuttiness. Feel free to experiment with combinations to create a unique flavor profile that suits your taste.

Is this dish suitable for vegetarians?

Yes, this recipe is vegetarian as it primarily consists of vegetables, dairy, and seasonings. Just be sure to check that the cheese you use is vegetarian-friendly. It's a satisfying dish that can be enjoyed by everyone at the table.

Nutrition is estimated from USDA FoodData Central ingredient data and may vary with brand, portion and preparation — see our methodology. This information is for general educational purposes only and is not medical or dietary advice (disclaimer).

American recipes → Vegetarian recipes → Dairy recipes → All recipes →