Preheat the oven and prep the tomatoes - Preheat your oven to 350º F. Wash, destem, and deseed the tomatoes. It's OK if you don't remove all of the seeds - no worries. Dice the cleaned tomatoes into 1/2 to 1 inch chunks.
Add the tomatoes to your baking dish - Peel and smash the garlic cloves. Pour the tomatoes in to your baking dish. It's OK if they fill up the dish. just don't fill to the point where it's difficult to stir them. Scatter the smashed garlic cloves over the tomatoes. Add salt and pepper and a glug of olive oil, then stir it all together to ensure that every last tomato is coated with the oil.
Roast - Roast for about 1 ½ to 2 hours, stirring every so often. If the edges of a few of the tomatoes get a little char, it's all good. That's flavor!
Fill the Ziplock bag and freeze - Spoon the roasted tomatoes into the Ziploc bag Seal (pushing out as much air as you can), label the bag, and stash it in freezer.