Cheesy tuna melts

Name: Cheesy tuna melts
Prep time: 10 min
Total time: 10 min
Cuisine: British
Ingredients: 200g can tuna , whatever type you've got in the cupboard; ½ a bunch of spring onions , finely chopped; 4 tbsp mayonnaise; 3thick slices of granary or wholemeal bread; 50g cheddar , coarsely grated; generous pinch of paprika