Grandpa Joe's
Gratin Potatoes Parmigiano

Can you mix French and Italian in a title?  I hope so because it best describes a superb accompaniment to almost any meal.

About this recipe

Gratin is a technique used in food preparation that results in the dish being topped with a browned crust, and as everyone knows, potatoes are most frequently used in gratin recipes.  Almost any vegetable could be substituted for the potatoes, however.  This recipe works best with freshly-grated cheeses.  I recommend using your favorite sharp cheddar cheese and, most important, imported Parmigiano-Reggiano cheese.

Ingredients

  • 6 tablespoons unsalted butter
  • 6 tablespoons all-purpose flour
  • 3 cups whole milk
  • 4 ounces sharp cheddar cheese
  • 4 ounces Parmigiano-Reggiano cheese
  • 3 pounds russet potatoes
  • 1 sweet onion, sliced
  • kosher salt
  • cayenne pepper

Directions

  1. Roughly grate the cheddar and Parmigiano-Reggiano cheeses.  Four ounces should produce a heaping cup of each cheese.
  2. Melt the butter in a heavy saucepan.  Add the flour and stir until smooth.  Cook over low heat for about 5 minutes. 
  3. Add the milk, raise the heat to medium, and begin whisking gently.  When the milk begins to thicken, add the grated cheeses in ½ cup increments, whisking continuously.
  4. When the sauce begins to boil, lower the heat and continue whisking for another minute.  Then remove the sauce from the heat.
  5. It is important to add salt at this point, but only a small amount is required.  Taste the sauce, add ¼ teaspoon kosher salt, and taste again to experience the difference.  Add more salt if desired.
  6. Whisk in 1/8 teaspoon cayenne pepper.  Cover, and set aside.
  7. Peel and slice the potatoes into ¼-inch slices (using a mandolin if available).  Begin by spreading a layer of cheese sauce over the bottom of a casserole dish (see Notes).  Next, create a layer of overlapped potato slices.  Work in circles, beginning at the outer edge of the dish.  Then create a second layer of potato slices.  Top the second layer with pieces of sliced onion.  One onion slice, separated into half rings is usually sufficient for each double layer.  Sprinkle with kosher salt, and cover with the cheese sauce.
  8. Repeat the layering process two more times, creating a total of three double layers.  Add all of the remaining cheese sauce after the third double layer.  Cover with a lid or aluminum foil.
  9. Bake in a preheated 350° F oven for one hour.  Remove the cover and bake for an additional hour, or until the top is nicely browned.
Gratin Potatoes Parmigiano.
Gratin Potatoes Parmigiano with ham, fresh green beans, and Garlic Bread.

Notes

  • I recommend using a high-sided (about 4-inches), four-quart casserole dish for this recipe.  Also, a round or square dish is preferred over an oval dish to promote more even cooking.
  • At the risk of undermining my opening comments above, any cheese can be used in this recipe, but I do prefer freshly-grated.
  • Add a pound of cooked (and diced) ham and you have a main course!
  • This dish can be prepared through step 8 and then refrigerate for up to 2 days.  Add another 30 minutes to the first baking time in step 9.
Posted: February 2014.