First, select a nice bone in turkey breast. Boneless turkey breasts are just plain weird. They take all the meat hunks and press them into a lump and wrap mesh around it. Not terribly appetizing - take my word for it. I can fit up to an 8 pound breast in my 6 quart oval crock pot, though that is definitely pushing the limit. You'll definitely be safe with one around 7 pounds. Thaw it, either by putting it in the fridge a couple days in advance, or if you're like me and you decide that you've got a hankering for turkey dinner that morning, pull it out of the freezer and let it sit in a sink full of hot water for a couple hours. That size of a bird actually thaws relatively quickly. Remove the nasty gravy packet from the chest cavity and throw it away, then rinse the bird off and stick it in the crock pot, breast side down.
I used to remove the skin before cooking. It's a horrid job, and I've lately found that it slips off quite easily after cooking, plus lends better flavor to the broth if you leave it on. Since I hate to handle raw meat, I now leave it on.
Next, tuck 5-6 cloves of garlic in and around the breast, grind some freshly ground pepper over it all and sprinkle a generous pinch of kosher salt. Tuck 4-5 sprigs of fresh rosemary in and around (you can use dried as well, but the flavor of fresh is really worth it), and last of all a tablespoon of brown sugar. For more savory flavor, you can toss a peeled whole shallot into the cavity.
Put the lid on. If you're like me and tend to choose bustier turkey bosoms than your crock pot can handle, you might wind up with a gap between the lid and the pot. Like this one. There was a centimeter gap. So I simply placed a towel over the lid, followed by a layer of tin foil, and then pulled out some old sacks of beans that have been pressed into service for this very thing a number of times, and weighted the lid down. Works like a charm, but I wouldn't push it any farther than I did.
Set it to cook on low for 8 hours or high for 6. Walk away and let the pot do it's magic. When the cook time is up, pull the breast out and flip it upside down on a plate. Tent it loosely with foil and let the juices settle for at least 10 minutes before pulling the meat off. Usually, the meat literally just falls off the bones in two neat breasty hunks, which are super easy to slice for serving.
Now it's time to make gravy. Easy stuff, I promise. I slurp all of the juices out of the pot with a turkey baster and pour them into a pyrex cup. I usually get around 2 cups. (Notice that I did not have to add any water to the pot to achieve this - it's pure turkey magic.) Melt 2 T. of butter in a large nonstick skillet over medium heat, then whisk in 2 T. flour until it forms a thick paste. Slowly whisk in the turkey juices, bit by bit, making sure that you incorporate the flour well and smoothly. Once all the juices have been added, correct the seasoning as needed with a little more pepper (I have never needed to add more salt) and let simmer for 2-3 minutes. Done!
This is such moist and tender turkey that you may never cook a full bird again. I have hosted Thanksgiving before with only this kind of turkey. I lined up three pots in the garage, and voila! Not only did I have perfect turkey that everyone swooned over, but I also didn't have it competing for oven space.