Lazy House Meat Option:
Chicken thighs (preferably boneless for lazy factor), rosemary, sea salt, pepper, chicken broth. (Other seasonings if you like -- I forget which others we sometimes add in, it varies.)
Throw in thighs in layers as flat as you can, apply layer of seasonings, continue until mostly full. Pour in broth. Slow cook whilst at work. Come home to a week's worth of awesome protein. (That's with our slow cooker, which is big-ish, but my husband eats like he's trying to power a fusion reactor, so it kinda balances out.)
You will be tempted to use some other cut of chicken for this, because chicken thighs in a big pack are often cheap enough to look seriously shady on principle (they're almost always on sale everywhere). Don't. Seriously. It's just not as good with chicken breasts or a mix, and you will have spent more to get there.