5 cups yellow and/or red pear-shape or round cherry tomatoes
1 cup thinly slivered sweet onion (such as Maui, Vidalia, or Walla Walla)
1/2 teaspoon crushed red pepper
6 cloves garlic, thinly sliced
2 1/4 cups white balsamic vinegar
3/4 cup water
1/3 cup sugar
3 tablespoons pickling salt
1 tablespoon fresh rosemary leaves
1/2 teaspoon whole black peppercorns
1/2 teaspoon whole pink peppercorns
1/2 teaspoon whole white peppercorns
1 bay leaf
Wash tomatoes. In a large bowl combine tomatoes, onion, crushed red pepper, and garlic; toss gently to combine. Set aside.
In a large stainless-steel, enamel, or nonstick heavy saucepan combine vinegar, the water, sugar, salt, rosemary, black peppercorns, pink peppercorns, white peppercorns, and bay leaf. Bring to boiling, stirring until sugar dissolves; reduce heat. Simmer, uncovered, for 10 minutes, stirring often. Remove and discard bay leaf.
Pack tomato mixture into hot, sterilized half-pint canning jars, leaving a 1/2-inch headspace. Pour hot vinegar mixture over tomato mixture in jars, leaving a 1/2-inch headspace. Remove any air bubbles in jars. Wipe jar rims; adjust lids.
Process filled jars in a boiling-water canner for 15 minutes (start timing when water returns to boiling). Remove jars from canner; cool on wire racks.