Grandma's Famous Potatoes Au Gratin

Indulge in the timeless comfort of Grandma's Famous Potatoes Au Gratin, a rich and creamy classic that’s guaranteed to steal the spotlight at any meal. Featuring layers of tender, thinly sliced Russet potatoes smothered in a velvety sauce made from sharp cheddar, Parmesan, and a hint of aromatic garlic and thyme, this dish is the perfect blend of decadence and nostalgia. Topped with a golden crust—enhanced by optional crispy panko bread crumbs—each bite delivers a satisfying crunch followed by a melt-in-your-mouth experience. With a prep time of just 25 minutes, plus a bubbling 75-minute bake, this recipe is ideal for cozy family dinners and festive occasions alike. Impress your guests with this iconic comfort food, packed with flavor and irresistibly creamy textures!

Nutriscore Rating: 65/100

Prep Time:25 mins

Cook Time:75 mins

Total Time:100 mins

Servings: 6

Ingredients

• 6 medium Russet potatoes
• 4 tablespoons Unsalted butter
• 1 medium (finely diced) Yellow onion
• 2 cloves (minced) Garlic
• 3 tablespoons All-purpose flour
• 2.5 cups Whole milk
• 0.5 cup Heavy cream
• 2 cups (shredded) Sharp cheddar cheese
• 0.5 cup (grated) Parmesan cheese
• 1 teaspoon Salt
• 0.5 teaspoon Black pepper
• 0.25 teaspoon Paprika
• 1 teaspoon Fresh thyme leaves
• 0.5 cup Panko bread crumbs (optional)

Directions

Step 1

Preheat your oven to 375°F (190°C) and grease a 9x13-inch baking dish with butter or non-stick spray.

Step 2

Peel the potatoes and slice them thinly into 1/8-inch rounds using a sharp knife or mandoline slicer. Set the sliced potatoes aside in a large bowl of cold water to prevent browning.

Step 3

In a medium saucepan over medium heat, melt the butter. Add the diced onion and cook until soft and translucent, about 3-4 minutes. Add the minced garlic and cook for another 30 seconds until fragrant.

Step 4

Sprinkle the flour over the onion mixture and whisk constantly for 1-2 minutes to form a roux.

Step 5

Gradually pour in the milk and heavy cream, whisking constantly to remove any lumps. Cook until the mixture thickens slightly, about 3-4 minutes.

Step 6

Reduce the heat to low, then stir in the shredded cheddar, grated Parmesan, salt, black pepper, paprika, and thyme. Stir until the cheese is fully melted and the sauce is smooth. Remove from heat.

Step 7

Drain and pat the sliced potatoes dry with a clean kitchen towel. Layer half of the potatoes evenly on the bottom of the prepared baking dish.

Step 8

Pour half of the cheese sauce over the potatoes and spread it evenly. Repeat with the remaining potato slices and cheese sauce to create two layers.

Step 9

If using panko bread crumbs, sprinkle them evenly over the top for added crunch.

Step 10

Cover the baking dish with aluminum foil and bake in the preheated oven for 45 minutes.

Step 11

Remove the foil and bake uncovered for an additional 25-30 minutes, or until the potatoes are tender and the top is golden and bubbly.

Step 12

Remove from the oven and let the dish rest for 10 minutes before serving. Garnish with additional thyme or parsley if desired.

Nutrition Facts

Serving size	(2302.2g)

Amount per serving	% Daily Value*
Calories	3630.3

Total Fat 196.8g	0%
Saturated Fat 120.7g	0%
Polyunsaturated Fat 0.7g
Cholesterol 603.8mg	0%
Sodium 4963.8mg	0%
Total Carbohydrate 340.2g	0%
Dietary Fiber 23.0g	0%
Total Sugars 48.2g
Protein 132.9g	0%

Vitamin D 268.4IU	0%
Calcium 3043.1mg	0%
Iron 14.7mg	0%
Potassium 7026.5mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 48.3%

Protein: 14.5%

Carbs: 37.1%