Onions Au Gratin

In the NutriGuide test kitchen, Chief Culinary Specialist Stewart Lucas refined this classic Onions Au Gratin to celebrate vibrant, wholesome ingredients. By prioritizing aromatic layering and precise thermal control, this recipe achieves remarkable culinary depth while preserving natural micronutrients and wholesome texture.

At NutriGuide, our mission is to ensure that home cooking is both accessible and culinary-grade. When executing Onions Au Gratin, focus on fresh aromatics, dry surface contact for proper searing, and allowing the food to rest before serving.

• 1/4 cup butter
• 6 yellow onions, halved and sliced
• 1/2 inch thick
• 1/2 cup beef broth
• 1/2 cup heavy cream
• 2 tablespoons all-purpose flour
• 1/4 teaspoon salt
• 1/8 teaspoon pepper
• 1/2 cup shredded Swiss cheese
• 1/2 cup grated Parmesan cheese

Chef's Sourcing & Quality Tips:

• Produce & Aromatics: Always use fresh whole aromatics and seasonal herbs rather than dehydrated powders when possible.
• Cooking Oils: Utilize cold-pressed oils with appropriate smoke points such as extra virgin olive oil or avocado oil.
• Salt & Seasoning: Season from a modest height above the pan to ensure an even, uniform crystalline dispersion.

Follow these sequential steps with careful attention to sensory cues and cooking temperatures:

Step 1: Technique & Execution

Preheat the oven to 350 degrees F (175 degrees C)

Step 2: Technique & Execution

Grease an 8 inch square baking dish

Step 3: Technique & Execution

Melt the butter in a large skillet over medium heat

Step 4: Technique & Execution

Add onions; cook and stir until tender, about 5 minutes

Step 5: Technique & Execution

Transfer to the prepared baking dish

Step 6: Technique & Execution

In a medium bowl, stir together the beef broth and flour until smooth