The basic recipe for this classic British pub food is incredibly simple — the filling is nothing more than cheddar, and onion. In traditional cheddar onion pie, onions are cooked without browning. But this recipe is more or less totally different from that. Instead, we’ve caramelised the onions to dark, sticky sweetness. It works well as a side dish, as part of a brunch spread, or as an appetiser. Whenever we make it, it’s always one of the most popular things on the table.