To make the filling, melt the butter, add the mushrooms and cook for 3-4 minutes until golden.
Remove from the pan and set aside.
In the same pan, add the oil and chopped onions, and fry them until translucent.
Add the ground turkey and use a wooden spoon to break it into small pieces.
Cook it until no longer pink and juices released are absorbed.
Add the chopped carrots, mushrooms, chopped tomatoes and stock.
Cook for 15 minutes or until the liquid is mostly absorbed.
To make the sauce, melt the butter, add the flour, and whisk well.
Pour in the milk, and continue to whisk to get a smooth sauce.
Add the cheeses, dijon mustard and black pepper.
Mix well, then remove from the heat.
To assemble, add 2-3 tablespoons of the filling onto a tortilla wraps, rolled it, and arrange on an oven-proof dish.
If the dish is not large enough, arrange the enchiladas on 2 layers, spreading sauce and cheese after each layer.
Bake in the preheated oven at 180 degrees Celsius (350 Fahrenheit) for 10-15 minutes until the cheese is melted and bubbling hot.