No, no, no, no, no. We're answering the last question first. The government, sanitation experts, cookbook writers, the busboy at Applebee's - essentially the whole of the food world - is working hard to see that you don't pour leftover marinade over cooked meat. If the surface of a piece of meat is contaminated, cooking it would kill the harmful bacteria. But if you took it out of the pan or off the grill and put it back on the cutting board or plate that you used to prepare the meat, or poured your delicious marinade over it, you could re-introduce the contamination.

If you keep your ears open in the food world, you'll occasionally hear the phrase "cross contamination," and this is exactly what it is referring to - the prospect of contaminating a properly prepared food with one that may be harboring some problem. Some people have color-coded cutting boards that are dedicated to certain tasks - one is only ever used for meats, another is only ever used for fruits and vegetables. We think you can get cutting boards safely clean, and don't feel the need to segregate our boards, but the practice highlights a determination to avoid cross contamination.

We don't think you need to live in a frightened haze of anti-bacterial soap, but there are other simple steps you can take to ensure that you are minimizing your exposure to contaminants. Don't cut tomatoes for your salad with the knife you just used to trim a piece of meat. In general, keep cooked and uncooked foods separate. Wash raw fruits and vegetables thoroughly. Wash your hands, cutting boards, and cooking utensils frequently with soap and hot water.

Back to your marinade, if you bring it to a boil while the meat is cooking, you will ensure that it is also free of harmful bacteria and can certainly use it as a sauce for the meat.

Now, as to the first and much more difficult part of your question, there are thousands of marinades, and there is not a specific one dedicated to London Broil. You can prepare one of the marinades already available from Ochef (click on the Related Articles below). Or if you'd like something more basic, consider one of these: Jean Paré's Favorite Marinade, based on soy sauce, sherry, and vinegar, Alehouse Steak Marinade based on beer and various flavorings; or, for a completely different approach, Coca-Cola Marinade for Flank Steak.