You might want to try a combination of yukon gold and russet potatoes - alternate them in rows as you lay them out in the baking dish and season with salt and pepper. Gruyere cheese and cream will give the best flavor, at least the flavor I prefer. Add minced garlic and minced thyme to the shredded gruyere, toss together and spread between layers of potatoes, one third at a time and saving the last third for the top after you’ve poured on a cup or two of cream. Don’t cook the potatotoes in advance, and and don’t soak them in water, but do slice them using the thinnest cutter on the mandoline and assemble and cook the gratin immediately so the potatoes don’t turn grey.
