Method
Preparation
Preheat your oven to 375°F (190°C).
Thinly slice the Yukon gold potatoes and onion.
Making the Sauce
In a saucepan, melt the butter over medium heat. Add the onions and sauté until soft.
Stir in the flour and cook for a minute, then gradually whisk in the almond milk. Cook until thickened.
Remove from heat and stir in the cheddar, garlic powder, salt, pepper, gruyere, and parmesan until melted.
Assembly
Layer the potatoes in a baking dish, pour the cheese sauce over them, and top with parsley.
Baking
Cover with foil and bake for about 1 hour.
Remove the foil and bake for an additional 15-30 minutes until the top is golden and bubbling.
Let it cool slightly before serving.
Notes
Let the dish rest for 5 to 10 minutes after baking for better slice retention. It pairs well with roasted meats or fresh green salads. Can be stored in the fridge for up to 4 days.