I never heard of a "loose meat" sandwich until they appeared on Roseanne I dunno how many years ago, when the main character based the restaurant she opened, the Lunch Box, around her famous recipe for loose meat sandwiches. Not long afterwards, being a new resident to central Illinois, I visited my first Maid-Rite. The sandwiches there were pretty good -- though I think they tasted better if you have a nostalgic attachment to them.
Then last year, I had one of my sister-in-law's loose meat sandwiches. I'm not even sure if that's what she called them, but they were ground meat sandwiches, the filling for which she had warmed in the Crockpot. It was her grandmother's simple recipe, and I'm telling you, I could have eaten fifty of them. In reality, I think I may have eaten just over twenty.
I recently made up my own recipe based on what she told me was in those (I'm sure she would have given me the recipe over the phone, but if I'm often too lazy to look at a recipe, I'm definitely too lazy to pick up the phone). I think I got really close, although I think she may have used meat with a higher fat content. I had very lean ground beef, which as usual, had only made it into our house because I had to buy some to make something else to bring to a crowd of people.
The difference between these and say, a Manwich or a Sloppy Joe is that basically they aren't as tomato sauce-y, and there aren't any green peppers in them. The ingredients that you add cook down enough so that all that is left is their enhancement of the meat itself.
First, I added the following ingredients to the food processor:
1 cup celery
1 cup onions
1 cup carrots
3 cloves garlic
Pulse those until everything is very finely chopped, but not puréed. Then add the vegetables to a large sauce pan or skillet, and wilt the vegetables with a bit of olive oil, salt and pepper. Then add about 1.5 pounds of ground meat, and brown it (drain if you wish, which will yield a leaner end product). Add about 1 cup ketchup, 1/2 cup mustard, and a little brown sugar. Season it again.
I simmered mine together right there in the pan for about 45 minutes, or until the meat is crumbly, and the other ingredients are no longer recognizable as separate entities, so to speak. It should just look like ground meat. You could also transfer it to a slow cooker immediately after the browning phase, and place it on "low," and let it simmer in there until you achieve the same result. (Couple hours, probably).
I served the sandwiches with Trader Joe's greens, cooked with broth, onions, garlic, and their thick-cut turkey bacon... There reheated very well, were delish with a little cheddar on them, and tasted very, very good. You can double or triple the recipe to feed a crowd, too!