Step 1

Tip the tuna into a bowl with the spring onion, red onion and cheddar. Use a fork to flake apart the tuna and mix everything together. Add the mayonnaise, lemon juice, lots of pepper and a little pinch of salt and fold together.

Step 2

Sandwich the filling between the two slices of bread, then butter the outsides of the sandwich.

Step 3

Heat the oil in a frying pan over a low heat. Add the sandwich and immediately sit a clean, small, flat-bottomed saucepan on top with a tin inside to squash the toastie down. Fry for 4–5 minutes, or until the bottom is crisp and golden and the filling is starting to ooze – if it browns quicker than this the filling won’t be melted enough. Flip and repeat to cook the other side. If it’s perfectly toasted but the filling is not quite melted enough, pop in the microwave for a minute. Serve immediately.