Otherwise known as pytt-i-panna ("mess-in-a-pan") or hänt-i-veckan ("happened-this-week")
I made that the other day - but I cheated and didnt really use leftovers, I did it from scratch
Bit like the Brits have bubble-and-squeak, the Swedes have pytt-i-panna.
My recipe:
All the following, diced:
potato
onion
bacon
mushroom
beetroot
Fry that lot up (adding them to the pan in that order), add some seasoning to taste (like garlic, or paprika, or both, mmm), and then fry an egg or two to put on top