Meanwhile, make jam. Spray 10-inch skillet with cooking spray; heat over medium-high heat. Add reserved onion and garlic to skillet; cook 3 minutes, stirring frequently, until golden. Add brown sugar and lemon juice, stirring to loosen browned particles from bottom of skillet. Stir in remaining jam ingredients; break up tomatoes with spoon. Heat to boiling; reduce heat. Simmer uncovered 20 minutes, stirring occasionally, until mixture begins to thicken. Strain jam though fine strainer; discard liquid.