Ingredients:

  • 2 lbs (900g) Russet Potatoes, peeled
  • 4 cloves Garlic, minced
  • 4 tbsp (57g) Unsalted Butter
  • 1/4 cup (30g) All-Purpose Flour
  • 3 cups (720ml) Whole Milk
  • 1 cup (115g) Shredded Parmesan Cheese
  • 1/2 tsp Dried Thyme
  • Salt and freshly ground Black Pepper, to taste
  • 1/4 cup (approx. 30g) shredded Gruyere (optional, for extra richness)

Instructions:

  1. Preheat oven to 375°F (190°C). Grease a 9x13 inch baking dish.
  2. Slice potatoes thinly (about 1/8 inch thick).
  3. Melt butter in a saucepan over medium heat. Add garlic and cook until fragrant (about 30 seconds).
  4. Whisk in flour until smooth. Gradually whisk in milk until no lumps remain.
  5. Bring to a simmer, stirring constantly. Cook until slightly thickened.
  6. Remove from heat and stir in Parmesan cheese, thyme, salt, and pepper.
  7. Layer potatoes in the prepared baking dish, pouring sauce over each layer.
  8. Top with Gruyere cheese (if using).
  9. Bake for 50-60 minutes, or until potatoes are tender and top is golden brown.
  10. Let rest for 10 minutes before serving.