We visited Las Vegas a few years ago on Spring Break. We ate in the rotating "Top of the World" restaurant above the Stratosphere. The view was spectacular, and the food was yummy. Their signature Potatoes Au Gratin, with gorgonzola, parmesan, provolone and romano cheese, was particularly noteworthy.
I've never found "their" recipe, but I've found a similar recipe that we like a lot and modified it to incorporate a blend of cheeses. If you've made potatoes au gratin, you've probably discovered it is difficult - if not impossible - to get the potatoes in the middle to cook without overcooking or curdling the sauce. But this recipe will yield perfectly done potatoes every time, because it cheats: you parboil the potatoes first, then heat through just enough to get everything bubbling hot.
Potatoes Au Gratin
Ingredients: 3 cups diced cooked potatoes (with or without skins); drained
6 tablespoons unsalted butter
3 tablespoons flour
1 1/2 cups milk
1/2 cup grated Parmesan or Romano cheese (not the stuff in the plastic shaker jar)
1/2 cup diced or grated soft cheese (soft mild fontina is my favorite, but provolone, Monterey Jack or mozzarella can be substituted)
1/4 cup crumbled feta, blue or gorgonzola cheese
1 cup soft bread crumbs
Directions:
Grease au gratin pan or 1-quart casserole dish. Add still-warm potatoes to pan and set aside. In a heavy saucepan over medium-low heat, melt butter; pour half into a cup or bowl and set aside. Add flour to the remaining 3 tablespoons and stir well; allow to bubble into a light roux. Gradually add milk, whisking constantly. Continue cooking, stirring constantly, until sauce has thickened - make sure there are no lumps. Add cheeses and stir until they begin to melt. Pour sauce over potatoes in baking dish; mix gently to coat. Combine butter with bread crumbs and sprinkle over potatoes. Bake about 15 minutes to heat through; switch to broil and broil just until golden and bubbly on top. Serves 4.
This recipe can be doubled for a crowd, and the lineup of cheeses can be changed to suit your preferences (and what you have on hand.) But don't shy away from the blue cheese if you're worried about it overpowering the dish...there's just enough there to add a hint of pungent flavor that even blue-cheese haters will enjoy, without the "bite" they don't.
Happy cooking!