While I'm sure that there is so much similarity between photos of lemon tarts (or whatever dish), I would NOT use a stock photo for it. Readers want to see something YOU created. It's more genuine and authentic.
Two more thoughts:
1. Imagine if someone called you out on the photos. For example, "I see that your (whatever) looks like this. Mine doesn't. Why?" Then you'd have to say, "Well, it isn't my photo." Now imagine how the reader would feel. They'll feel duped and would question your authority.
2. Stock photos of food are tough to do! That's why some photographers specialize in it. So these stock photos may look too perfect. People want authenticity.