This is just a classy variant on cheese-on-toast, but can make a really tasty starter, or fairly substantial nibbles in the bar (for when there's a long wait while dinner is cooking).
Classically, this is made with french bread batons - long thin sticks which can be cut into rounds. Alternatively, use a large pastry-cutter and cut the centres out of ordinary white or brown bread. This also works with wheat-free sliced bread, which is the only kind that Tracey now eats.
Pre-heat the oven to Gas Mark 6 or 200 Celcius. Arrange the rounds of bread on a metal baking tray. Drizzle a few drops of olive oil onto each one. They put into the oven for 5 to 10 minutes to crisp up, while you investigate the fridge for some toppings.
Basically, the toppings are cheese-and-something, but feel free to use different cheeses: Brie, Camembert, strong Cheddar, almost anything!
And with the cheese, something else, something spicy or tangy. Pieces of Anchovy fillets. Slivers of salami or ready-cooked bacon. Capers. Lemon pieces (with the rind cut off). Sun-dried tomatoes, cut into quarters. Olives, sliced in half. Or try smearing the toasts with bottled chilli sauce before adding the cheese. Or Pesto. Or Tapanade. Go wild!
Pull the crispy bread out of the oven and arange the toppings. They'll need to go back into the oven for just a few minutes, until all the cheese is melted. Serve immediately.
I usually make three different kinds, with whatever I can find in the fridge (yes, leftovers!), and challenge my guests to work out what's in each one - and which one they prefer.