You're not in the wrong here imo. Saying someone is an amazing person doesn't mean you want to cheat on your gf with that person. You're good, she's being a bit insecure and unreasonable. Have you got any history with said person for her to feel this way?
Just drop it.
I'm not entirely sure I could tell the difference between home-made and store-bought, so I don't see your point here. There are many variables.
Anyway, by now she probably thinks you're weird, so it would matter anyway.
You're not in the wrong here imo. Saying someone is an amazing person doesn't mean you want to cheat on your gf with that person. You're good, she's being a bit insecure and unreasonable. Have you got any history with said person for her to feel this way?