I have bits of this ad stuck in my head, I think it was some chain restaurant (a la Denny's), featuring a chef singing a version of "Toreador" about their new breakfast (sandwich?) as he prepares it.
I think it might have been some kind of sandwich because the one line I (likely mis-)remember goes like:
Then a piece of freshly made toast
Put it right in the middle!
I can't find it anywhere online, and honestly I'm starting to wonder if I hallucinated the whole thing. Someone please help cure my earworm!