# What you'll need:
→ Vegetables
01 - 2.5 lbs russet or Yukon Gold potatoes, peeled and thinly sliced
02 - 1 small yellow onion, thinly sliced
→ Dairy
03 - 2 cups whole milk
04 - 1 cup heavy cream
05 - 2 cups sharp cheddar cheese, shredded
06 - 1 cup Gruyère or Monterey Jack cheese, shredded
07 - 4 tablespoons unsalted butter
→ Pantry & Spices
08 - 3 tablespoons all-purpose flour
09 - 1 teaspoon garlic powder
10 - 1 teaspoon salt, plus more to taste
11 - 1/2 teaspoon ground black pepper
12 - 1/4 teaspoon smoked paprika
13 - Chopped fresh chives or parsley, for garnish (optional)
# Method:
01 - Preheat oven to 375°F. Grease a 9x13-inch baking dish with butter.
02 - Melt butter in a medium saucepan over medium heat. Add flour and whisk continuously for 1-2 minutes until bubbly but not browned.
03 - Gradually whisk in milk and cream. Continue whisking until the mixture thickens, approximately 3 to 5 minutes.
04 - Stir in garlic powder, salt, black pepper, and smoked paprika. Remove from heat.
05 - Add 1½ cups shredded cheddar and ½ cup shredded Gruyère cheese to the sauce. Stir until melted and smooth.
06 - Arrange half of the sliced potatoes in an even layer in the baking dish. Top with half of the sliced onions.
07 - Pour half of the cheese sauce evenly over the potatoes and onions.
08 - Add remaining potatoes and onions in layers, then cover with the remaining cheese sauce.
09 - Sprinkle remaining shredded cheddar and Gruyère cheeses evenly over the top.
10 - Cover dish tightly with aluminum foil and bake for 45 minutes.
11 - Remove foil and bake an additional 25 to 30 minutes until potatoes are tender and top is golden and bubbling.
12 - Allow the dish to rest for 10 minutes before garnishing with chives or parsley and serving.
