This being Christmas Eve, I'm sure a lot of you are arm-deep in either wrapping paper or cooking activities. Anyone who's ever seen me wrap presents knows why my wife banishes me to another part of the house while she handles that task, so I'll stick to the kitchen questions.

Before we get into the questions, let me wish all of you a very merry Christmas and a (belated) blessed Yule! May all your recipes be tasty, and all your families content.

Q: What is the difference between regular salt, kosher salt and sea salt when they are called for in recipes? Are they interchangeable? Francis P.

A: Ah, one of my favorite questions! Salt is a topic upon which there are volumes and volumes written. The differences among types can be confusing. As concisely as I can make it, here we go:

Kosher salt: Kosher salt is "pure" salt. It has no additives and thus gives the cleanest, truest flavor. Its large flakes make it ideal for coating meats and any topical application, but it is harder to dissolve in liquids than table salt. If you (and I strongly recommend doing so) substitute kosher for table salt in a recipe, use slightly more, as the flake form makes it measure a bit lighter by volume. A tablespoon of kosher salt is roughly equivalent to two teaspoons of table salt. This is a great example of why weight measurement is always best!

Table salt: Iodized or not, table salt contains additives which can alter the taste of cooked materials. It also dissolves very quickly, so using it as part of a dry rub or on a steak before broiling is wasted effort. Keep this stuff on the table, where it belongs. (Although I prefer kosher salt for the table, too.)

Sea salt: On my last trip to Central Market, the official Houston grocery temple, I encountered a French sea salt for which I could have paid almost $80 a pound. I demurred in favor of five pounds of dry-aged standing rib roast. Now, for high-line gourmet recipes, especially seafood, sea salt can be a must. However, due to its high content of minerals other than good old sodium chloride, it is most definitely not recommended for everyday cooking.

Q: If you do not have self-rising flour, can you just add one teaspoon of baking powder in the recipe? E. Platt

A: Very close! For each cup of flour, add 1 ½ tsp. baking powder and ½ tsp. salt to make all-purpose flour substitute for self-rising.

For all sorts of great information on ingredient substitutions, check out this page put up by the good folks at Land O' Lakes. (See? Butter people RULE!)

Q: I am going to attempt to make a beef tenderloin for Christmas. I never have done this, so I am very nervous. I have looked at several recipes and wonder how will I know for sure when it is done to our likeness? At what temperature would it be medium-well done? A lot of the recipes I read said to cook in the oven for 45 minutes. Is that right? I still do not know if I will try this. Any suggestions? Thanks. --Linda G.

A: The best thing you can do with any chart, recipe, stone tablet or wall hanging that purports to tell you, by time, how long to roast a piece of meat is throw it out. I prefer incineration, so bad information has no chance to spread.

There is one, and ONLY one way to reliably measure when a roast is done, and that's with a probe thermometer. In my experience, the best model consists of a base unit with a large, easily readable display and a magnet for mounting on oven doors, hoods etc. The probe wire should be long and sturdy, and the probe long enough to sink into the heart of the stoutest roast.

Linda, I'm going to beg a little bit right now. PLEASE do not spend good money on a tenderloin and then cook it medium-well. Try it medium-rare just once, and I guarantee you'll be converted. Properly roasted, a medium-rare beef tenderloin is one of life's great joys.

To cook that tenderloin medium-rare, set your probe thermometer's temperature alarm to go off at 125 degrees F. When it sounds, remove the meat from the oven and allow it to rest, loosely foil-covered, for 15-20 minutes. Carve and enjoy! If you insist on medium-well, set that alarm for 140 degrees. I'll cry, though.

And, finally, my most important tip of the week: GET OUT OF THE KITCHEN and spend some time with your family!