Heat the oil in a frying pan over a medium heat until the pan gets fairly hot.
Sprinkle the cheese on one slice of bread and drizzle with the cranberry sauce. Top with the other slice of bread.
Put the sandwich in the pan and use a spatula to put some pressure on it. Grill on one side for 3-4 minutes, then flip over and repeat until both sides are golden and the cheese has melted. Serve immediately.