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Hollandaise sauce

The sauce can make or break the eggs benny. It all needs to be good though, but if the sauce is just a bit off, it ruins the lot since it gets into everything.

My test for places varies, but Garlic Bread is a good one, and if it's a burger joint, Cheeseburger. And of course anything they put the restaurant name on (such as a <storeName> special). If they stuff up those things, they aren't going to be a decent place to return to