Cook broccoli for 5 minutes in lightly salted boiling water, until only just tender. Drain well and place in a shallow flameproof dish.
Heat the butter and the oil in a heavy-based saucepan and fry the onions for about 5 minutes until softened.
Add the chicken and continue to fry until the chicken is cooked about 10 minutes.
Stir in the flour and cook gently for 1 minute.
Gradually add the milk and stock stirring well. Bring gently to the boil stirring constantly, until sauce thickens. pour the chicken mixture over the broccoli.
Mix together cheese and breadcrumbs and sprinkle over chicken dish. Place under a preheated grille and cook until the cheese melts and the topping is golden and crisp.
You can add the broccoli stems as well if desired, slice finely and cook with the florets.Not suitable for freezing.Nutrition information is approximate (does not include seasoning with salt and pepper) and is meant as a guideline only.