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

Sauté the Vegetables: Heat the olive oil in a large frying pan over a medium heat. Add the diced onion and green pepper and cook for 5-7 minutes, until softened. Add the minced garlic and cook for another minute until fragrant. Remove from the heat and set aside.

Make the Sauce Base (Roux): In a medium saucepan, melt the butter over medium heat. Whisk in the plain flour and cook for one minute, stirring constantly. This cooks out the raw flour taste.

Create the Creamy Sauce: Gradually pour in the warm chicken stock, whisking continuously to prevent lumps. Bring the mixture to a simmer and cook for 2-3 minutes, until it has thickened. Remove the pan from the heat and let it cool for a minute or two.

Finish the Sauce: Whisk in the sour cream, drained green chillies, ground cumin, and dried oregano. Season with salt and pepper to taste. It’s important not to return the sauce to a high heat after adding the sour cream, as it can curdle.

Combine the Filling: In a large mixing bowl, combine the shredded chicken, the sautéed onion and pepper mixture, and about 100g of the grated cheddar. Pour in about 200ml (a good ladleful) of the white sauce and mix everything together until the chicken is well-coated.

Assemble the Enchiladas: I find that warming the tortillas for 15-20 seconds in the microwave makes them much more pliable and less likely to split. Spoon the chicken mixture evenly down the centre of each tortilla, then roll it up tightly and place it seam-side down in your prepared baking dish. Repeat with the remaining tortillas.

Bake to Perfection: Pour the rest of the white sauce evenly over the rolled tortillas, making sure to cover them completely. Sprinkle the remaining 100g of grated cheddar cheese over the top. Bake for 20-25 minutes, or until the sauce is hot and bubbly and the cheese is melted and golden brown. Let it rest for 5 minutes before serving.