The original text of the recipe, taken from Gheeraert Vorselman, Eenen nyeuwen coock boeck (edition recipe I.17, p.109).
Solaet van pastinaken. Neemt pastinaken ende siet se wel, ende ghiet dat water uut; dan neemt versch water ende siet se in dat water weder met lactouwen; dan doet se in een schotel ende doet er op sout, azijn, corianden ende peperpoeder. Men mach se ooc frijten in boter oft oly na dat se eens ghesoden is ende binnen het hert uut ghedaen ende in die bloemen ghewentelt.

English Translation from the Coquinaria site
Salad of parsnips. Take parsnips and boil them well, and pour off the water. Then take fresh water and boil them in this water with lettuce. Then put them in a dish, and add salt, vinegar, coriander and ground pepper. You can also fry them in butter or oil once they have been cooked and core has been removed, and [the slices] have been covered with flour.

My recreation
3 parsnips
2 small heads of romaine (yields about 8 cups of shredded leaves)
1/2 cup white wine vinegar
1 tbsp. coriander seeds
½ tsp black pepper
2 tsps salt

  1. Scrape skins from parsnips
  2. Cut into ½ inch rounds (they may have been thinner, it was an eyeball)
  3. Boil fresh water, when it comes to a boil put in 1 tsp of salt, then add parsnip pieces
  4. Boil for 10 minutes and drain
  5. Wash and shred 2 heads of romaine
  6. Boil fresh water, when it comes to a boil put in 1 tsp of salt, then add the precooked parsnips and the fresh romaine.
  7. Boil for 1 minutes
  8. Drain and shock in an ice bath*
  9. Grind the coriander and black pepper, and add to the vinegar.
  10. Mix vigorously
  11. Drain the parsnips/greens from the ice bath
  12. Coat with the vinegar mixture

*(this is not a medieval method, but blanched lettuce will retain its green this way)