Only once, and NEVER AGAIN! Ever. It will never happen again. For reals. Sort of. Maybe. If you want to get technical and go 100% by what Tedd is describing in the last panel.
Tedd's right, of course. Not about being a horrible cook. Tedd can do a decent job if she's in the right frame of mind. In regard to their safety, however, If Mr. Verres believed that Grace's brothers were close, he wouldn't leave them without some sort of protection, It's a safe bet there's nothing to be worried about whatsoever.