Wrap the potatoes in foil and put them on the coals. Leave them there for 35 to 40 minutes.
Cut the tomatoes into four wedges each and scoop out the core. Then finely dice the pieces. Chop the red onion and chilli finely. Finelize the salsa by adding lime juice, a little olive oil and the chopped coriander. Season with salt and black pepper to taste.
Make a cut in the cooked potato and dig out some of the insides using a spoon. Add the salsa and finish by crumbling feta cheese on top.