I'm not even a big tomato eater and these things are addictive to me. A friend brought these to a game day get together and they were devoured quickly. There isn't really a set recipe so I will pass it along the way it was given to me and that I have done a few times now with good success.
Get a bunch of roma tomatoes - I think this batch in the pictures, maybe I did 15 or so, I wouldn't bother doing it with any less.
Quarter up the tomatoes and cut out all of the seeds and juicy, loose part of the inside. You'll just have basically the "meat" of tomatoe on the skin
Lay them out skin side down on a sheet pan or two or three sheet pans depending on how big a batch you are making.
Drizzle with olive oil and sprinkle with garlic salt, garlic powder and italian seasoning. The key here is, when you think you have put enough, double it up and put more...and then put some more. Even the olive oil. Then take them and mix them all around make sure everything has a really good coating, then arrange them back up skin side down. Annd why not throw a little more of the seasonings on top.
Throw them in the oven on 250 for at least 3 hours, you may need to re-arrange the outside ones and move them to the middle depending on how they cook at some point while cooking. This batch I think I probably actually went 4+ hours. You're really looking for them to get a nice dark roasted color.
The first picture below is before I put them in the oven, the second picture below is when they came out of the oven and the third is how I snacked on them - on a slice of toasted baguette with a little cheese spread or just straight on the bread. I just throw them in a tupperware and keep them in the fridge. They are also good to cut up and put into pasta dishes, chicken dishes, in soups, on pizza's, etc