Ingredients
Pasta
- 1 pound short cut pasta, cooked according to package directions
Sauce and Vegetables
- 4 tablespoons unsalted butter
- 1 sweet onion, diced
- 3 garlic cloves, minced
- Pinch of salt and pepper
- 4 tablespoons flour
- 12 ounces fresh baby spinach
- 2 1/2 cups milk
Cheese
- 12 ounces fontina cheese, freshly grated
- 6 ounces white cheddar, freshly grated
- 2 ounces parmesan cheese, freshly grated
Topping
- ½ cup crispy onions or breadcrumbs
Instructions
- Preheat and sauté aromatics: Preheat the oven to 350 degrees F. Heat a large oven-safe pot over medium-low heat and add the butter. Stir in the diced onion and minced garlic with a pinch of salt and pepper. Cook, stirring often, until the onions have softened and become translucent.
- Cook the pasta: Meanwhile, cook the pasta in another pot according to package directions. To prevent sticking, toss the cooked pasta with a quick spritz of olive oil and set aside.
- Prepare cheese blend: Toss together all the grated cheeses—fontina, white cheddar, and parmesan—in a bowl, reserving a small amount of cheese for topping later.
- Make the roux and sauce: Stir the flour into the softened onions to create a roux. Cook for 2 to 3 minutes, stirring continuously until it becomes golden in color and develops a nutty aroma. Slowly stream in the milk while stirring constantly to avoid lumps. Continue stirring as the mixture thickens into a creamy sauce.
- Add spinach: Add the fresh baby spinach to the sauce. Although it seems like a large amount at first, cook and stir until the spinach wilts down and softens.
- Combine pasta and cheese sauce: Stir in almost all of the cheese mixture (keeping some for topping) and then fold in the cooked pasta. Toss repeatedly over low heat until everything is thoroughly combined and the cheese is melted.
- Assemble and bake: Top the mac and cheese with the remaining grated cheese and sprinkle the crispy onions or breadcrumbs evenly on top. Place the pot or transfer to an oven-safe dish if needed, then bake in the preheated oven for 25 to 30 minutes until the top is golden brown and bubbly.
Notes
- For best results, use freshly grated cheese rather than pre-shredded to ensure smooth melting.
- If you prefer a crispier topping, use panko breadcrumbs toasted in butter instead of crispy onions.
- Feel free to substitute whole milk with 2% for a lighter option.
- This dish can be prepared a day in advance, assembled, and refrigerated before baking—just add a few extra minutes to the baking time if refrigerated.
- Leftovers reheat well in the oven or microwave but may require adding a splash of milk to maintain creaminess.
- Prep Time: 25 minutes
- Cook Time: 45 minutes
- Category: Main Course
- Method: Baking
- Cuisine: American