Combine the cheddar with the emmental or mozzarella and the spring onions in a small bowl.

Spread the mayonaise over one side of each slice of sourdough. Pile the cheese mixture over the plain sides of the bread, then spoon over the kimchi. Sandwich the slices together so the mayo-coated sides are on the outside, then sprinkle with sesame seeds, if using. Heat a large frying pan or skillet over a medium heat. Arrange the toasties in the hot pan and weigh them down with another heavy pan. Cook for 4-6 mins, then turn over and cook for 5 mins more. Cut in half to serve. Twist it BLUE CHEESE Swap the grated cheddar for a blue-veined stilton or cambozola for a punchier flavour. LEFTOVER KIMCHI Use any leftover kimchi in a rice- or noodle-based stir-fry made with pak choi, then serve with a fried egg on top. It also makes a fantastic dip – just blitz in a food processor with some soured cream and soft cheese until smooth.