
One of the reasons that I'm attracted to the study of medieval Salads is that I feel they allow some scope for creativity. After having looked at a bunch of salad receipes, I am pretty sure that the ingredients of a salad, boiled or otherwise, varied depending on what was available; what made it a salad was the possible selection of greens and other foods, plus the dressing, specifically with oil, salt and vinegar.
By the late 16th century we are looking at sugared salads such as sugared lemons. Over time, sugar became associated with salad dressings and it was also associated with pickles. But from the Forme of Cury to Castelvetro, we are looking primarily at salads with oil, salt and vinegar.
Fancied up salads, such as Markham's, decorated with pickled or sugared flowers, cut-outs from root vegetables, and so on are also a late 16th and early 17th century trend.
How do medieval salads differ from modern ones? Well, limiting it to the raw salads, we are looking at a greater variety of greens than we would see in a modern American salad on average. The dressing is simple, but the greens/herbs are also more tangy/bitter than we would see at our local restaurant. Flowers appear more often. We also have the large category of 'boiled sallets' which have mostly disappeared (except for dandelion greens with hot bacon dressing and their ilk).
So, you use a variety of tangy greens, wash them carefully, dry them, mingle them with salt, oyle and vinegar.