French Onion Mac and Cheese 

This indulgent French Onion Mac & Cheese from How Sweet Eats transforms classic macaroni into a rich, caramelized‑onion masterpiece. Sweet onions are slowly caramelized until deeply golden, then folded into a creamy Gruyère-Parmesan cheese sauce layered with pasta and baked until bubbly. Finished with a thyme-infused breadcrumb topping and sprinkled with fresh thyme, it’s a show‑stopping side or vegetarian main—perfect for holiday meals or cozy dinners. Serves a crowd with comforting, savory depth in every cheesy bite. 

Ingredients

• 3 Tbsp olive oil
  
  

• 4 large sweet onions, thinly sliced
  
  

• Kosher salt & pepper
  
  

• 1 lb short-cut pasta, cooked
  
  

• 3 Tbsp unsalted butter
  
  

• ¼ cup all‑purpose flour
  
  

• 2½ cups whole milk
  
  

• ¼ tsp freshly ground nutmeg
  
  

• 12 oz Gruyère cheese, freshly grated
  
  

• 4 oz Parmesan cheese, freshly grated
  
  

• ⅓ cup seasoned breadcrumbs
  
  

• Fresh thyme, for serving
  
  

Directions

1. In a large oven-safe skillet, heat olive oil over medium heat. Add onions and a pinch of salt. Cook 10–15 minutes until softened, then reduce heat to low/med‑low and caramelize slowly—stirring often—for 60–90 minutes until deep golden. Add a few splashes of water if needed to prevent burning.
   
   

2. Preheat oven to 375 °F. Meanwhile boil pasta to al dente per package directions.
   
   

3. Transfer most of the caramelized onions to a plate, reserving a little for topping.
   
   

4. In the same skillet, melt butter, whisk in flour to form a roux—cook 2–3 min until golden and nutty. Slowly pour in milk, whisking constantly until thickened. Stir in nutmeg.
   
   

5. Off the heat, whisk in most of the cheese until smooth, then return senior onions and cooked pasta. Stir to combine thoroughly.
   
   

6. Top with remaining cheese, reserved onions, and breadcrumbs. Bake for 25–30 minutes until bubbly and golden brown. Remove and garnish with fresh thyme. Serve warm.
   
   

Nutrients

Based on similar French onion mac & cheese recipes and servings scaled to 12 portions:
Calories: ~210 kcal
Carbohydrates: ~24 g
Protein: ~10.5 g
Fat: ~10 g
Fiber: ~1.5 g
Sugar: ~3 g
Sodium: ~350 mg