Simple, cheap, potentially trigger-free, and an American classic, meatloaf is one of the great ways to feed a family with a migraine patient. As a starting point, check out the Hillybilly Housewife recipe for meatloaf.
A few notes are in order:
1) Shallots, not onions
2) Make your own breadcrumbs. Throw one or two pieces of toast in a food processor and you have trigger-free breadcrumbs. Breadcrumbs in this recipe are for texture, not taste, so no need to season them.
3) If you use the food process for both breadcrumbs and veggies (makes prep REALLY fast), make the breadcrumbs first. Otherwise, the breadcrumbs get soggy and are a little harder to work with.
4) Food snobs use fresh garlic. To me, garlic is about tradeoffs. Fresh is best, but requires prep and results in stinky hands. A garlic press is a good workaround. Minced garlic in a jar is faster and easier, but it's not minced as fine as I would prefer. Garlic powder is easy to use, measure and store, and is the only choice where only dry ingredients will do (see Taco Seasoning, for instance), but is otherwise inferior to fresh or pre-minced.
5) Experimentation is possible with this recipe. Different breading will provide different texture. Also, differing amounts of liquid will provide different texture. I prefer the texture with little or no liquid, but it makes the meat more resistant to mixing. You can vary your liquid too: beef or chicken stock work great as flavor enhancers. Finally, you can vary the vegetables you put in the mix. Peppers are always good, or you may have other favorites that you'd like to try.
6) A good cook ordinarily tastes their food to check seasoning. That's not safe with raw meat, so you can take a meatballs worth (about 2 tablespoons) and fry it in a small patty like a burger to check it.
7) Ketchup is not allowed. One of the best alternatives to ketchup for meatloaf is gravy. Gravy is so important to migraine cooking that a separate article will be devoted exclusively to gravy.
8) Leaner cuts of meat produce less grease, but the grease is very easy to pour off. Don't spend more on ground sirloin if that is a stretch for you.
Again, this is very hard to screw up, so try this and have some fun.