Personally, I feel your Dom isn't strong enough for you. At no point should a sub be 'too much' for a Dom/Master. And honestly, the things that you are naming shouldn't bother a real Master. So you want to order your own food. So what? It's nothing to get bent out of shape. Can your sub/slave do 'something' on her own once in a while? Just because someone is a Dom or Master doesn't mean that the sub can't (or shouldn't) fend for herself at a restaurant. So she doesn't want onions. Let her tell the waiter. But let be get back on topic (because you don't have a problem with this behavior).

Let your Master help you with this one. The point of discipline is to get rid of bad habits like the one you mentioned. Every time he feels you've stepped out of line, you can expect a punishment when you get home (and not the good kind). Enough punishment and pretty soon you'll learn to hold your tongue.