Q. I recently had a scallop dish at a favorite restaurant of mine. When I asked the server how they were prepared, he said they were cooked not with heat but by the dressing. They were really good, but is this safe? If so, can I do this at home?
A. You were enjoying a Latin American specialty: ceviche, a dish in which scallops (or other seafood) are "cooked" without heat. Instead they are marinated in an acidic dressing, which "cooks" them by changing the makeup of the proteins.
You can change the protein by cooking with a physical process, as when heat is used, or by a chemical process, which happens when an acid like lemon juice is applied to meat or fish.
You can definitely make ceviche at home. Just make sure you buy very fresh scallops or whatever other type of fish you choose. Also, make sure the pieces are not too large; otherwise, you will turn the outside into mush and the inside will still be raw.
If you use scallops, bay scallops are already just the right size. I prefer the flavor of sea scallops, but since these are larger, they would have to be sliced.
Q. I have one problem. Why does my chocolate ganache lose its shine a few hours after frosting a cake?
A. If you are going to go to the trouble of making a gorgeous cake or torte, the last thing you want is for the icing not to look perfect.
For all the people out there wondering what the fuss is all about, let me explain it this way. Ganache is to chocolate lovers what the Federal Reserve is to bank robbers: the ultimate goal.
Ganache is made of high-quality semisweet chocolate and whipping cream that have been heated and mixed together until the chocolate has melted.
Once the mixture has cooled to lukewarm, it is poured over a cake or, better yet, a flourless chocolate torte, and, let me tell you, it's hard to find something that tastes better.
If you are losing the shine, you might want to try one of two things. First, make sure your chocolate and cream mixture cools down sufficiently before you pour it over your cake. If it is too hot, you will usually see streaks in the chocolate surface.
Second, you might want to add about a tablespoon of light corn syrup to your ganache as it is cooling. This will help it retain its shine. Also, stir - do not whip - your ganache.
Jim Coleman is executive chef at the Rittenhouse Hotel in Philadelphia, a cookbook author and host of television and radio cooking shows.