Heat the oven to 225 F. Bring a large pot of water to a boil, and set a bowl of ice water nearby.
Blanch the tomatoes to loosen their skins. University of Arkansas Cooperative Extension suggests cutting a small X in the bottom of each tomato, dunking it in boiling water for no more than a minute, then moving it to ice water. The skin will start to slip right off.
Peel the tomatoes, cut them in half, and scoop out the seeds. Save the seeds and juice in a freezer bag to add to soup later.
Lay the halves on a nonstick baking tray. Sprinkle with garlic, thyme, salt, and sugar, then drizzle with olive oil.
Bake for 3 hours.
Serve on Italian bread or burgers.
Notes
Cook's note: To store, layer the tomatoes in a jar with a basil leaf between each one, and cover with olive oil. Keep the jar in the fridge and use the tomatoes within 3 days.