Their shape won't change much in the oven, so flatten to whatever thickness you prefer. (ohladycakes.com)
If the sauce is a bit too thin, raise the heat to medium and simmer, uncovered, 5 - 10 minutes, until the thickness you prefer is reached. (goodstuff.recipes)
cut off any bad spots and slice your rhubarb into the thickness you prefer. (angelaskitchen.com)