Ingredients:

  • 1.5 lbs (680g) boneless, skinless chicken breasts, cut into 1-inch (2.5 cm) cubes
  • 1 tbsp (15 ml) olive oil
  • 1 medium yellow onion, chopped (about 1 cup / 150g)
  • 2 cloves garlic, minced
  • 1 head of broccoli, cut into florets (about 4 cups / 400g)
  • Salt and freshly ground black pepper, to taste
  • 4 tbsp (57g) unsalted butter
  • 1/4 cup (30g) all-purpose flour
  • 3 cups (720 ml) whole milk
  • 1/2 tsp Dijon mustard
  • 1/4 tsp ground nutmeg
  • 8 oz (225g) sharp cheddar cheese, shredded (about 2 cups), divided
  • 1 cup (100g) panko breadcrumbs
  • 2 tbsp (28g) unsalted butter, melted
  • 1 tbsp fresh rosemary, finely chopped
  • 1/4 cup (30g) grated Parmesan cheese
  • Pinch of salt

Instructions:

  1. Heat olive oil in a large skillet. Add chicken and cook until browned and cooked through. Remove chicken from skillet and set aside.
  2. In the same skillet, sauté onion until softened. Add garlic and cook until fragrant.
  3. Add broccoli florets to the skillet with the onion and garlic. Season with salt and pepper. Cook until broccoli is tender-crisp.
  4. Melt butter in a saucepan. Whisk in flour and cook for 1 minute to make a roux. Gradually whisk in milk and bring to a simmer, stirring constantly. Reduce heat and simmer until thickened.
  5. Remove from heat. Stir in Dijon mustard, nutmeg, and most of the shredded cheddar cheese (reserve some for topping). Stir until cheese is melted and smooth. Season with salt and pepper to taste.
  6. In a small bowl, combine panko breadcrumbs, melted butter, rosemary, Parmesan cheese, and salt.
  7. In the baking dish, combine the cooked chicken, broccoli, and cheese sauce. Stir to combine.
  8. Sprinkle the remaining shredded cheddar cheese evenly over the casserole. Then, sprinkle the rosemary crumb topping over the cheese.
  9. Bake in a preheated oven at 375°F (190°C) for 25-30 minutes, or until golden brown and bubbly.
  10. Let cool slightly before serving.