Cook the broad beans in boiling water for 2 minutes. Drain, refresh under cold water, drain again, then peel from their skins.
Use the back of a fork to roughly crush the beans with the olive oil and lemon juice, then stir through the mint. Season with salt and pepper to taste.
Cook the British asparagus in boiling salted water for 1 to 2 minutes then drain under cold water.
Heat a griddle pan, toast the bread on both sides, then rub with the garlic clove. Spoon some of the beans over each slice of bread, scatter over the British asparagus, mint and mozzarella and drizzle with more olive oil to serve.