boil the potatoes in salty water until tender,after cooked drain the water

beat the egg yolks with the mayonnaise and the mustard

add the mixture to the potatoes plus the onion and the bell pepper ,mix well

place in a greased oven tray

beat the egg withes until fluffy and double in volume and mix with the cheese season to taste and spread the mixture on top of the potatoes

take to oven at 400Funtil golden brown (about 20Mn)