I recently built a stovetop cover or "noodle board" using a hardwood so it can be used as a cutting surface. I stained it with minwax gel stain and from what i understand it should be food safe once it has cured properly. What i want to know is if it can be sealed with oil or wax once it has been stained.
Yes. The extent to which that is "sealed" is debatable, but there's certainly no issue with finishing over cured stain - it's done all the time.
Just stay food safe (and be sure to check with your guests about nut allergies if using something like walnut oil, which is a good food-safe hardening oil, but not great if you have a guest with tree-nut allergies at a very sensitive level...)
My dad used to seal all his handmade cutting boards with mineral oil. What I noticed was an odor which I didn’t care for. MOST mineral oils are petroleum based.
I found and use food grade board oil, as well as conditioner. The odor is much more palatable. AND- since I have a huge number of food allergies, much safer than nut based oils.