Slow Roasted Tomato Salsa

0 Preheat oven to 350°F / 177°C.
1 Line a sheet pan with foil. 
2 Spread tomatoes, onion, jalapeños, and garlic head halves out on sheet pan, cut side-up. Drizzle everything generously with oil and sprinkle with some salt. 
3 Place garlic head in a small piece of foil. Wrap the foil to fully enclose the garlic.
4 Bake vegetables, without stirring, until everything is very tender and onions are deep golden brown, 75 to 90 minutes. (The tomatoes should be very soft and jammy.)
5 Pour roasted tomatoes, onions, jalapeños, and any liquids from the roasting pan in a food processor or blender. Gently squeeze garlic cloves out of the garlic head into food processor. (You can use all of the roasted garlic if you like or start with half and add more to taste. This will seem like a lot of garlic but roasting it mellows the flavor.) 
6 Blend until no large pieces remain. 
7 Add cilantro, salt, cumin, and lime juice. 
8 Pulse until everything is evenly combined and nearly smooth. Add water, as needed, until the salsa is the right consistency for dipping chips. (Note: The amount of additional water needed will vary depending on the natural moisture content of the tomatoes. Some batches of salsa may not need any extra water, but some may need up to an additional 3/4 cup.)
9 Taste salsa and season with some more salt if needed. You can add some hot sauce if you’d like more heat. 
10 Salsa can be stored in the fridge for up to a week.