Peel and cut potatoes into four lengthways. Cut each slice into thin slices for chips. In a deep skillet with a lid fry potatoes and chopped onion in olive oil over medium heat, stirring occasionally until tender and become golden. If you stick add olive oil and reduce heat. Already ready squeeze them in a colander from fat. In a bowl beat eggs. Add potatoes, salted to taste and stir to mix well. In a small frying pan 13 cm Heat some olive oil to cover the bottom. Pour and spread the mixture well and fry with a lid on low heat. Move the pan occasionally to avoid sticking. When ready turn the other side. Turning it flat and smooth dish that sandwiching as lid on the pan and turn. Already facing the plate, slip back into the cake pan and fry the other side the same way. Conversion is the most complicated part, so be careful.