Sheet Pan Scalloped Potatoes with Ham and Peas

This dish is all the best of baked potatoes packed in a convenient form for dinner on a baking sheet. There is a lot of crispy cheese sprinkling on the baking sheet with a pleasant aroma of fresh thyme, the corners and edges retain a pleasant crisp crust, and in the center the potatoes are perfectly fried. Ham and peas make this dish complete, but not so much that it seems to someone that it is something other than home-made food. When adding the cheese sauce, shake the pan slightly to make sure that the sauce has soaked through the potato layers and set — this will ensure perfect distribution and prevent overflowing in the oven.
Preheat the oven to 450°F. Brush an 18-inch x 13-inch baking sheet with 1 tablespoon of butter.Melt the remaining 3 tablespoons of butter in a saucepan over medium-high heat. Add the garlic; cook, stirring frequently, until fragrant, about 1 minute. Add the flour; cook, whisking constantly, for 1 minute. Whisk in the cream and cook, stirring constantly, until slightly thickened, about 3 minutes. Remove from heat; add 2 cups of cheese and stir in the pepper and 2 teaspoons of salt. Stir until the cheese is melted and the sauce is smooth; add the peas.Place half of the potato slices and half of the ham on the prepared baking sheet. Brush the potatoes and ham with half the cheese sauce. Repeat the layers once with the remaining potatoes, ham, and cheese sauce. Cover a baking sheet with aluminum foil and bake in the preheated oven until the potatoes are tender, about 40 minutes.Combine panko, thyme, and remaining 3/4 cup cheese in a small bowl. Remove the foil and sprinkle the potato mixture with panko sprinkles. Return to the oven and bake at 450 ° F until the panko filling is golden brown, 20 to 25 minutes.