Place sliced Potatoes in a large saucepan and add Milk, Butter, Salt, Pepper, Onion Powder and Garlic Powder. Bring to a low boil and simmer for 3 minutes (the potatoes should still be slightly firm).
Bring milk/butter mixture back to a low boil and add Flour. Whisk well to avoid lumps.
When milk thickens add Grated Gruyere Cheese. Blend well and adjust seasoning.
Pour over potatoes and bake in a 350℉ oven for 40 minutes or until golden and bubbly. Garnish with fresh herbs.