Mix together the refried beans, spring onions, sweetcorn and coriander in a bowl.
Spread 1 tortilla with the bean mixture, top with the salsa and sprinkle over the cheese. Cover with the remaining tortilla.
Brush a large frying or griddle pan with oil and heat over a medium heat. When hot, add the quesadilla and cook over a medium heat for 2–3 minutes, pressing down with a spatula, until the cheese starts to melt.
Place a large plate over the pan and invert the quesadilla on to the plate. Return to the pan and cook on the other side for 2–3 minutes.
Remove from the pan and cut into wedges. Serve with tomato salsa.