2tablespoonsminced fresh rosemary,or thyme or basil or oregano
Preheat the oven to 225°F. Arrange the tomatoes in one layer in sheet pans. Scatter the garlic cloves among them. Drizzle the olive oil over everything and sprinkle everything with salt. Set in the oven for between 2 and 5 hours.
When the tomatoes have collapsed and have simmered for at least 1 hour, sprinkle the herbs over everything. Turn off the heat and leave the pans in the oven. Once everything has returned to room temperature, pack into containers. This will keep several weeks in the fridge.
If you happen to have large cherry tomatoes, slice them in half. And yes, this works with large tomatoes, but you will need to chop them.
Keys to Success
Ingredients matter. Use fresh tomatoes, and good olive oil.
Err on cooking this longer than shorter. You want the garlic to be soft. You want the flavors to marry.
Use whatever herb you like. I prefer rosemary, but oregano, marjoram, sage, mint, parsley, savory, basil, etc. are all very nice.
Puree this for a crazy good pasta sauce. Or just spoon it on as is.