One of the great ingredients in many recipes is stock. Although homemade stock avoids the problems of unknown added ingredients and by-products, it requires preparation and cold storage. After much time, effort and frustration, I've found a store brand of stock that works great in recipes, without the MSG, soy and other problematic ingredients: Kitchen Basics. They have a very strict policy regarding many common allergens, including several affecting migraine patients. WARNING: it does contain some ONION, but not enough to bother my onion-sensitive wife.
Although I use chicken, beef and vegetable varieties, I keep going back to chicken. Even when I make beef dishes, I sometimes use chicken stock for sauces, gravies and extra liquid. It goes well with pork and I use it in place of water sometimes in rice and risotto. However, beef and vegetable are good and provide a simple tool for some variety in your dishes. When considering salted versus unsalted, unsalted gives you an option if you are also managing sodium intake. Pros prefer unsalted because it allows the most control. I recently switched to unsalted, but find myself adding more salt to compensate. Unsalted is probably the better choice, but neither is strictly "wrong". My best recommendation is not to switch back and forth, as it is easier to misjudge appropriate amounts of added salt.
With so many sources of flavor creating problems for the migraine patient (MSG, soy, onions, most vinegar and wine, citrus, etc.), it is great to have stock on hand and a handful of delicious ways to use it.