Heat oven to 180°C bake. Cook the bacon. In a jug, whisk the milk and eggs together, and season with salt and pepper. Set aside.
Mix the butter and garlic together, then use a little to grease a shallow baking dish or tin. Use the rest to butter the bread slices, then cut them in half diagonally.
Arrange the bread slices, overlapping, in the baking dish. Tuck the bacon, cherry tomatoes and mushrooms in around the bread slices.
Pour the egg mixture over the bread (gently push the slices down in the liquid if need be). Leave to stand for 5 mins. Scatter the cheese and basil leaves over the top, then bake for 25–30 minutes until golden and just set. Garnish with extra basil leaves and serve with a spinach & cucumber salad and tomato chutney.