Best Onion Parmesan Gratin Recipes

PARMESAN-CRUSTED AU GRATIN POTATOES AND ONION

Steps:

• Place potatoes into a large pot and cover with water; add salt and bring to a boil. Reduce heat to medium-low and simmer until just beginning to soften, 15 to 20 minutes; drain.
• Melt butter in a saucepan over medium heat; add flour and whisk until the mixture thickens, 1 to 2 minutes. Pour milk and heavy cream into the saucepan; cook and stir until smooth, 2 to 3 minutes. Melt Cheddar and Asiago cheese into the butter mixture; cook while stirring continually until the mixture is smooth and creamy, 1 to 2 minutes. Season the sauce with salt and pepper.
• Preheat oven to 400 degrees F (200 degrees C). Butter a 9x13-inch casserole dish.
• Layer about half the sliced potatoes into the bottom of the baking dish. Top the potatoes with sweet onion slices and green onions; pour about 1/3 of the cheese sauce over the onions. Arrange the remaining potato slices into the dish; pour remaining cheese sauce over the potatoes. Sprinkle Parmesan cheese and crushed crackers over the top.
• Bake in the preheated oven until hot in the center and beginning to brown at the edge, about 30 minutes. Sprinkle parsley over the top of the dish to serve.

SWEET POTATO GRATIN WITH CARMELIZED ONION AND PARMESAN CHEESE

Steps:

• Preheat oven to 375°F. Oil a 8" x 8" baking dish. In a skillet, heat butter and add onions and garlic on low heat and cook for 15 minutes. Place 1 layer of sliced potatoes overlapping slightly, 1 layer of onions, drizzle cream and sprinkle with parsley, and 1/4 cup of parmesan. Continue to make layers until the dish is filled. Sprinkle remaining parmesan to top layer. Cover with foil and bake for 40 minutes and then uncover and continue baking for another 25 minutes until potatoes are tender and top is brown. Let it rest for 15 minutes. Additional Notes: Substitute parmesan with goat cheese.

ONION-PARMESAN GRATIN

Steps:

• Slice the onions in half lengthwise. Place, cut side down, on a cutting board and slice crosswise into very thin slices, and set aside.
• In a large, nonstick skillet, combine the butter, cloves, onions, thyme and salt. Cover and cook over very low heat until the onions are very soft, about 10 minutes. Taste and adjust the seasoning.
• Transfer the onion mixture to a gratin dish and smooth it with the back of a spoon. The recipe can be prepared several hours in advance up to this point. Cover and store at room temperature.
• Preheat the broiler. In a small bowl, combine the egg yolks and cream and whisk together well. Stir in the cheese. Pour the mixture over the onions in the baking dish. Place the baking dish under the broiler about 2 inches from the heat. Broil until the top is sizzling and golden, about 1 to 2 minutes. Serve immediately as a vegetable course or as an accompaniment to meat dishes.

ONION PARMESAN GRATIN

Steps:

• Slice the onions in half lenghwise, then cut crosswise into thin slices.
• In a large skillet melt butter, then add in onions, thyme, cloves, pepper and salt; cover with lid and saute until the onions are very soft (about 10-12 minutes) adjust the salt to taste (do not add in too much salt as the Parmesan is salty!).
• Transfer the onions to a buttered gratin dish or small casserole dish and smooth it out with a spoon.
• At this point you can cover and let sit at room temperature to broil later.
• Preheat the broiler.
• In a small bowl whisk together egg yolks and whipping cream, the stir in Parmesan cheese.
• Pour the mixture over the onions in the baking dish.
• Place under the broiler (about 2-inches from heat).
• Broil until the top is golden.
• Serve immediately.