Mini Burgers With Smoky Tomato Chutney

Ingredients

• 1 lb. tomatoes, cored and halved crosswise
• 1 small red onion, unpeeled, cut into quarters
• 1/4 cup golden raisins, coarsely chopped
• 1/4 cup sugar
• 1/4 cup cider vinegar
• 1 tsp. smoked spanish paprika
• 1/2 tsp. ground cumin
• 1/2 tsp. sea salt, plus more, to taste
• 1 garlic clove, chopped
• 1 lb. ground beef, 85 percent lean
• 1 tbs. minced fresh thyme
• 1/4 tsp. worcestershire sauce
• 2 tbs. unsalted butter, frozen
• 8 small dinner rolls, about 3 inches in diameter