Unique Savory Tomato Cobbler

UNIQUE SAVORY TOMATO COBBLER1 Vidalia onion, choppedOlive oil1 large fresh tomato, chopped3 T. minced garlic3 lbs. assorted small tomatoes, divided1 T. white wine vinegar1 T. cornstarchKosher salt/black pepper1 T. fresh thyme leaves1 ½ c. self-rising soft-wheat flour (Brand like White…