10 oz Yukon Gold potatoes, sliced thin
6 oz sweet potatoes, sliced thin
2 Poblano peppers, roasted and roughly chopped
1 1/4 cup Gruyere, shredded
1 1/2 cup smoked mozzarella, shredded (reserve 1/4 cup for finishing gratin)
1/4 teaspoon cayenne pepper, or more to taste
1/2 tablespoon of kosher salt
1/4 teaspoon of white pepper
1 1/2 cups of heavy cream
1 tablespoon fresh garlic, minced
1/4 cup caramelized onions (recipe follows)
Butter for greasing pan
Preheat oven to 350 degrees.
Butter large casserole pan.
Toss potatoes and peppers with garlic, cayenne, salt, and pepper. Layer in casserole dish with Gruyere, mozzarella, and caramelized onions.
Pour heavy cream over the top. Sprinkle reserved mozzarella on top.
Bake until golden on top and potatoes are tender (about 1 hour).
2 teaspoons extra virgin olive oil
2 teaspoons salted butter
1 medium yellow onion, fine julienne
Ground black pepper
Warm butter and oil over low heat in large shallow pan – add onions and cook stirring frequently until they become deep golden brown – about 25 minutes. Season with Kosher salt and freshly ground black pepper.