Preheat the oven to 200 degrees Celsius / 392 Fahrenheit with the top and bottom heat.
Melt the butter in a large frying pan. Fry the onion. Then fry the garlic and mushrooms for a few minutes.
Meanwhile, cook the broccoli and carrots in a pan of boiling water until al dente (approximately 5 minutes). Drain and set aside.
Add the flour to the onion, garlic and mushrooms, stirring well. Fry for about two minutes.
Add the stock and bring to the boil. Simmer gently until thickened.
Then stir in the crème fraîche, fresh herbs, cooked chicken and vegetables. Season to taste with salt and pepper.
To make the topping, mix the self-raising flour with the sugar. In another bowl, mix the buttermilk and melted butter together. Add the thyme and grated cheese, mixing until a sticky dough forms.
Scoop the chicken and vegetable mixture in the baking dish. Use an ice cream scoop to make balls of dough and place them on top of the chicken mixture. Leave some space between them as they will expand.
Bake for 30–35 minutes or until golden brown and cooked through. Enjoy!