Remove celery strings and dice into 5mm cubes. Mince the onion and microwave for 1 minute at 600W, then let cool. Cut potatoes into bite-sized pieces and soak in water, then drain. Halve the mushrooms.

In a bowl, mix ground meat, celery, onion, and seasoning ingredients (☆). Shape into bite-sized meatballs.

Heat olive oil in a pan and cook the meatballs over medium heat until browned, rolling them occasionally.

Add potatoes to the pan and sauté until they develop a golden crust.

Add mushrooms and sauté briefly. Sprinkle flour and cook until no longer powdery.