I can only assume that your "stoneware" is the porous type and not glazed, candelbc. Were it glazed ceramic (which some people call stoneware) you would wind up with "soggy bottom" syndrome ... the same as heating on a baking sheet.
In an oven, under the broiler, or in a toaster oven ... the key is air circulation so that air gets under the food. If previously fried foods are heated directly on a baking pan (with no air circulation under it) the moisture collects and "steams" on the bottom of the food ... thus "soggy bottoms".
"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain