Preheat the oven to 200C and locate a 25 - 30cm oven proof casserole dish with lid.
Prepare your vegetables: finely dice the onion and celery. Slice the mushrooms to your liking. Roughly chop the broccoli. Crush the garlic.
Add 1 tbsp butter to the casserole dish and put over medium heat. Add the celery and onion, cooking for 4 - 5 minutes until translucent.
Add the remaining 1 tbsp of butter and the sliced mushrooms. Continue cooking for 5 - 7 minutes until golden and caramelised.
Without cleaning the pan, add the mince meat and continue cooking, breaking it up with a spoon or spatula.
Once there are no visible pink bits in the meat, add the crushed garlic and herbs. Cook for 30 - 60 seconds until fragrant.
Add the wine, tomato paste, Worcestershire sauce and broccoli and stir through. Taste for salt and pepper. Put the lid on the pan and place in the hot oven for 15 minutes while preparing the mash. To prepare the mash, microwave the florets for 9 - 10 minutes in a microwave proof bowl with lid until very tender. Blend the mash with remaining ingredients except the cheese until silky smooth. Remove the pan from the oven and spread the mash cauliflower over.
Sprinkle with cheese and return to the oven for 10 minutes until golden and bubbling around the edges.
Let stand for a few minutes before serving with a fresh side salad, or some freshly steamed broccolini.