Preheat and Prepare: First, preheat your oven to 180°C (160°C fan). Lightly grease a 23x33 cm (9x13 inch) baking dish.

Sauté the Aromatics: In a large frying pan, heat the olive oil over a medium heat. Add the finely diced onion and cook for 4-5 minutes until it has softened and become translucent. Add the minced garlic and cook for another minute until fragrant.

Make the Filling: Remove the pan from the heat. Add the shredded chicken and 200g of the grated Monterey Jack cheese to the pan with the onions and garlic. Stir everything together until well combined. Set this mixture aside.

Start the Sauce: In a medium saucepan, melt the butter over a medium heat. Whisk in the plain flour and cook for about one minute, stirring constantly, to create a roux. This step is crucial for thickening the sauce.

Build the Creamy Sauce: Gradually pour in the warm chicken stock, whisking continuously to prevent lumps. Let the sauce simmer and thicken for 3-5 minutes. Reduce the heat to low, then stir in the sour cream, chopped green chillies, cumin, and oregano. Be careful not to let the sauce boil once the sour cream is added, as it can curdle. Season with salt and pepper to taste. What works best for me is tasting it at this stage to ensure the seasoning is perfect before it goes on the enchiladas.

Assemble the Enchiladas: Spread a thin layer (about 4-5 tablespoons) of the white sauce on the bottom of your prepared baking dish. This prevents the tortillas from sticking. Warm the tortillas briefly in the microwave or a dry pan to make them pliable. Spoon about 2-3 tablespoons of the chicken filling down the centre of each tortilla, roll it up snugly, and place it seam-side down in the dish.

Bake to Perfection: Pour the remaining white sauce evenly over the top of the rolled tortillas, making sure to cover them completely. Sprinkle the remaining 100g of Monterey Jack cheese over the top. Bake for 20-25 minutes, or until the sauce is bubbly and the cheese is melted and lightly golden brown on top.

Rest and Garnish: Let the enchiladas rest for 5-10 minutes before serving. This allows the sauce to set slightly and makes them easier to serve. Garnish with fresh chopped coriander or sliced spring onions if you wish.