Cut the cauliflower into florets and steam until tender.

In a frying pan cook the bacon until it is almost done, then add the leeks and cook together until the bacon is crisp and the leeks are soft.

Remove the bacon and break into pieces.

Turn the oven to a low broil.

In a small saucepan, melt the butter and add the flour and stir until totally combined.

Slowly add the milk stirring until all the lumps are out to make a white sauce.

Add the salt, pepper and cayenne pepper.

Put the cooked cauliflower in an ovenproof casserole dish and sprinkle with half the bacon.

Pour the sauce over the mixture.

Add the leeks and remaining bacon.

Top with the tomato halves.

Sprinkle with Panko breadcrumbs.

Broil until the top starts to brown and serve immediately.