Peas and Onions Au Gratin

Elevate your side dish game with this indulgent Peas and Onions Au Gratin, a creamy and cheesy casserole that’s perfect for cozy family dinners or special gatherings. This recipe combines caramelized yellow onions and tender peas with a rich Gruyere and Parmesan cheese sauce, all crowned with a golden, crunchy breadcrumb topping. The luxurious roux-based sauce, infused with garlic powder and dried thyme, adds depth and complexity to the dish, while the combination of olive oil and butter ensures every bite is silky and flavorful. Ready in just 45 minutes, this au gratin is a crowd-pleaser that pairs beautifully with roasted meats or stands out on its own as a vegetarian delight. For lovers of hearty casseroles and melty cheeses, this Peas and Onions Au Gratin is sure to become a favorite!

Nutriscore Rating: 63/100

Prep Time:15 mins

Cook Time:30 mins

Total Time:45 mins

Servings: 6

Ingredients

• 2 tablespoons olive oil
• 2 tablespoons butter
• 2 medium yellow onion
• 3 cups frozen peas
• 2 tablespoons all-purpose flour
• 1.5 cups whole milk
• 0.5 cups heavy cream
• 1 cup shredded Gruyere cheese
• 0.5 cups shredded Parmesan cheese
• 0.75 cups breadcrumbs
• 0.5 teaspoons garlic powder
• 0.5 teaspoons dried thyme
• 1 teaspoons salt
• 0.5 teaspoons black pepper

Directions

Step 1

Preheat your oven to 375°F (190°C). Grease a medium-sized casserole dish and set it aside.

Step 2

Heat 1 tablespoon of olive oil and 2 tablespoons of butter in a large skillet over medium heat.

Step 3

Peel and thinly slice the onions. Add them to the skillet and cook for about 10-12 minutes, stirring occasionally, until they are golden and caramelized. Remove from heat and set aside.

Step 4

Bring a pot of water to a boil. Add the frozen peas and cook for 2-3 minutes, just until tender. Drain and set aside.

Step 5

In the same skillet used for the onions, melt the remaining 1 tablespoon of butter over medium heat. Add the flour and whisk continuously for 1-2 minutes to form a roux.

Step 6

Slowly add the milk and heavy cream to the roux, whisking constantly to avoid lumps. Cook for 3-4 minutes until the sauce thickens.

Step 7

Reduce the heat to low and stir in the Gruyere cheese, Parmesan cheese, garlic powder, dried thyme, salt, and black pepper. Mix until the cheese has melted and the sauce is smooth.

Step 8

Add the cooked peas and caramelized onions to the skillet, and gently toss them in the cheese sauce until evenly coated.

Step 9

Transfer the mixture to the prepared casserole dish, spreading it into an even layer.

Step 10

In a small bowl, mix the breadcrumbs with the remaining 1 tablespoon of olive oil. Sprinkle the breadcrumb mixture evenly over the top of the casserole.

Step 11

Bake in the preheated oven for 20-25 minutes, until the top is golden brown and the edges are bubbling.

Step 12

Allow the dish to cool for 5 minutes before serving. Enjoy your Peas and Onions Au Gratin!

Nutrition Facts

Serving size	(1497.0g)

Amount per serving	% Daily Value*
Calories	2533.9

Total Fat 157.3g	0%
Saturated Fat 77.2g	0%
Polyunsaturated Fat 3.8g
Cholesterol 389.7mg	0%
Sodium 5468.8mg	0%
Total Carbohydrate 183.2g	0%
Dietary Fiber 32.1g	0%
Total Sugars 60.5g
Protein 101.9g	0%

Vitamin D 189.5IU	0%
Calcium 2194.9mg	0%
Iron 13.4mg	0%
Potassium 2176.8mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 55.4%

Protein: 15.9%

Carbs: 28.7%