Preheat oven to 180°C.
Heat the oil in a large pot and quickly brown the chicken cubes.
Add the onions to the same pan and sauté lightly. Add the mushrooms and garlic and cook for a further 7 minutes, or until soft. Remove from heat and set aside.
Boil the broccoli in salted water until just tender.
Combine the chicken, broccoli and mushrooms in an ovenproof dish.
In a separate bowl, mix the contents of the sachet of the KNORR Naturally Tasty Chicken & Broccoli Bake with some milk. Stir well and pour over the chicken.
Sprinkle cheese on top and bake at 180°C for 30 minutes, or until golden brown on top.
Serve with pasta or mashed potato.