Let's answer some questions asked of me recently regarding cooking school (esp. LCB Paris) and vegetarians / those with food allergies.
I'm a vegetarian. Do they make you taste the dishes that include meat?
The purpose for the tastings at the end of class is so that you know how a well-prepared dish should taste. It is also so that you can replicate the recipes appropriately. If you're vegetarian and choose not to taste, remember that this can affect how well you cook. Guesswork doesn't really cut it if you don't understand the finished product.
My question back to you who are vegetarians: why are you going to cooking school? If you don't want to taste any meat and don't plan on cooking it, find another program that tailors to your diet. (Keep in mind that it's difficult in France.) But if you plan to work in a restaurant and are fine knowing that you will be cooking meat, consider tasting the plates in the beginning to really build a foundation for what reduced sauces and stocks taste like. Remember that you don't have to actually eat what you make in practical class, and there are plenty of people you can give the food away to. Just taste!
One classmate was vegetarian not for ethical reasons, but because her body didn't digest meat well. She still tasted to understand the final product, especially sauces that were stock-based. Every recipe we made during practical in the Cuisine program included meat of some kind.
At our official class dinners, the sign-up sheet always included an option for vegetarian meals. However, there wasn't an option for vegans. Talk to the people in charge of coordinating these dinners if you need a special meal. Don't be afraid to ask- after all, you've paid for the dinner and should enjoy it!
I'm allergic to XYZ. Will I still have to cook with it?
First of all, understand your food allergy before you begin classes. Are you allergic to peanut oil or just peanuts? Are you allergic to just the raw form or all forms? What do you do if you accidentally eat it? If you don't understand your allergy, you can't expect others to understand or help you.
Figure out how to politely say "I am allergic to XYZ" in French or whatever language your cooking school is in. At LCB, if you informed the chefs of your allergy, you didn't have to cook with that ingredient. If you tell the chefs when you first get there, some can be quite accommodating and will prepare a tasting for you that doesn't include what you're allergic to. However, this doesn't work if you're allergic to lobster and the main ingredient is lobster. In that case, just cook it and don't taste! Even if you can't eat the result, at least you spent more time in the kitchen and gained some experience.
If you are extremely allergic to something, be cognizant of the fact that there is a lot of cross-contamination between ingredients in the kitchen. Some people still cooked with ingredients they were allergic to but wore gloves (and obviously didn't eat the finished product). Err on the safe side and don't eat anything you're suspicious about.
Know what the offending ingredient looks like. This may sound silly and obvious, but if you are allergic to all nuts, know what a blanched and a roasted almond looks like. This way, you don't accidentally eat it because of ignorance.
Last but not least, pay attention during demonstration. An offending ingredient might not be in the recipe, but the chef might be spontaneous and decide to add it into the recipe.
Hopefully I've covered the questions thoroughly. Let me know under Comments if I can further clarify!