Boil potatoes in salted water for 5-10 minutes until tender.
Drain potatoes and pass through a ricer or mash thoroughly.
Mix potato, egg yolks, flour, and cheese into a soft dough and season.
Roll the dough into 1cm diameter logs on a floured surface.
Cut logs into 2.5cm pieces.
Boil gnocchi in salted water for 1-2 minutes until they float.
Remove gnocchi with a slotted spoon and drain on kitchen paper.
Fry gnocchi in oil for 1-2 minutes until golden-brown and crisp.
Drain fried gnocchi on kitchen paper.
Fry onion and squash in oil for 1-2 minutes in a hot pan.
Add garlic and rosemary for one minute, then simmer with stock until tender.
Blend soup until smooth, stir in cream, and season to taste.
Ladle soup into bowls, add gnocchi, and garnish with cress and pumpkin oil.