Preheat oven to 400° F. Line a rimmed baking sheet with aluminum foil.
Rinse the cherry tomatoes in a colander and shake excess water off. Transfer to a bowl. Add the slivered garlic, basil, olive oil for roasting, balsamic glaze, salt, and cracked pepper. Toss and then spread evenly on the baking sheet.
4 pints multi color heirloom cherry tomatoes, 6 cloves garlic, slivered, 6 fresh basil leaves, cut into slivers, ¼ cup olive oil (for roasting), ⅛ cup thick balsamic glaze, 1 teaspoon salt, ¼ teaspoon cracked pepper
Bake 45 minutes, checking occasionally, until the tomatoes and garlic are wrinkled, collapsed, and fragrant.
Remove baking sheet from the oven and let cool for 10 minutes. Transfer the roasted tomato mixture into a bowl or fill small jars. Fill so that you have at least 1" head space, and top off with olive oil so the tomato confit is sealed from air.
olive oil for topping off jars
Store in your refrigerator up to 1 month, freezer 3 months. Alternatively, use the link in the notes to get the Ball Canning instructions for Hot Water Bath method of canning and store in your pantry up to 18 months.