Ingredients
Scale
- 500g fresh or frozen green peas (if frozen, no need to thaw)
- 2 tablespoons unsalted butter
- 1 medium onion, finely chopped
- 2 cloves garlic, minced
- 3 tablespoons all-purpose flour
- 2 cups whole milk, warmed
- 1 cup grated mature cheddar cheese (or a mix of cheddar and Gruyère for deeper flavour)
- 1/2 cup grated Parmesan cheese
- 1 teaspoon Dijon mustard
- 1/2 teaspoon freshly ground black pepper
- 1/4 teaspoon freshly grated nutmeg (optional but adds a lovely warmth)
- Salt to taste
- 1/2 cup breadcrumbs (preferably fresh or panko for crunch)
- 2 tablespoons olive oil or melted butter (for topping)
Substitution tips: If you want a lighter version, swap whole milk for semi-skimmed, or use a dairy-free milk like oat milk with a splash of olive oil to mimic richness. For a vegetarian option, ensure your cheese is free from animal rennet. And if you’d like to add texture, chopped cooked bacon or caramelised shallots make delightful additions.
Instructions
- Preheat your oven to 180°C (350°F). Lightly grease a medium-sized baking dish with butter or oil.
- In a large pan, melt the butter over medium heat. Add the finely chopped onion and cook gently for about 5 minutes, until softened and translucent, stirring occasionally. This slow cooking brings out the onion’s natural sweetness, just like my mum taught me.
- Add the minced garlic and stir for another 30 seconds, being careful not to burn it — that fragrant aroma always reminds me of early mornings in our Devon kitchen.
- Sprinkle the flour over the softened onions and garlic, stirring constantly to form a roux. Cook for 2 to 3 minutes until the mixture bubbles and looks smooth; this step is crucial for a silky sauce without lumps.
- Gradually pour in the warmed milk, whisking continuously to avoid any clumps. Keep stirring until the sauce thickens enough to coat the back of a spoon — about 5 to 7 minutes.
- Remove the pan from heat. Stir in the Dijon mustard, nutmeg (if using), black pepper, and a pinch of salt. Then fold in the grated cheddar and half the Parmesan until melted and glossy.
- Gently fold in the green peas, ensuring they’re evenly coated with the cheesy sauce. If you’re using frozen peas, no need to thaw them first; the hot sauce will cook them perfectly.
- Pour the mixture into your prepared baking dish, smoothing the top with a spatula.
- In a small bowl, mix the breadcrumbs with olive oil or melted butter, then sprinkle evenly over the casserole. This topping adds a delightful crunch that contrasts beautifully with the creamy filling.
- Bake in the preheated oven for 25 to 30 minutes, or until the top is golden brown and bubbling around the edges.
- Let the casserole rest for 5 minutes before serving — this pause lets the sauce settle and makes it easier to serve. My mum always insisted on this little patience ritual, and I’ve found it makes all the difference.
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Category: Main Dish
- Method: Cooking
- Cuisine: International
