Celery and Potato Soup for 4

Scaled to serve 9

112.5 g of margarineheattosssimmer 30minblend
1012.5 g of celerycut into 1.5cm pieces
618.8 g of potatoespeeled, cut into 2.5cm cubes
2025.0 ml of chicken stock
2.2 bouquet garni
2.2 salt and pepper