Bread muffins, not cake muffins. The tuna mixed with fried spring onions and mayonnaise (out of a squeezy bottle) and topped with Edam before going in the oven. I decided not to put in the sunflower seeds; I should have used more Edam.
I’ve generally thought of putting things like this in the oven as too much faff, but the microwave combination oven preheats very quickly, and the whole thing is much nicer than if it had been stuck under the grill.
Also, we don’t normally buy Edam, but the flavours work really well.