The class was focusing on an early 17th C sweet (swete) bag. A picture can be found here.
While the class was not doing an exact reproduction, we were trying for the essence. The petals of the rose were started near the center with a bar. Then from this bar we did detached buttonhole. You could have done trellis stitch or hollie point so long as after the first couple rows the edge was detached and long enough to curl. In the last row we added in a piece of purl pearl - or you could have whipped the edge to add the purl pearl. If we had wanted to add additional petals they would have been started the same way and made smaller or completely detached and then added as you would in stumpwork.
The Burrell Collection, from which this piece was chosen, has a number of beautiful stumpwork pieces. Most of them were done in a satin or long/short stitch. Not quite sure why when they were contemporaneous pieces.
Hope this helps