3 pounds ripe plum tomatoes, cut in half lengthwise
1/4 cup plus 2 tablespoons good olive oil
1 tablespoon kosher salt
1 1/2 teaspoons freshly ground black pepper
2 cups chopped yellow onions (2 onions)
6 garlic cloves, minced
2 tablespoons unsalted butter
1/4 teaspoon crushed red pepper flakes
1 (28-ounce) canned plum tomatoes, with their juice
4 cups fresh basil leaves, packed
1 teaspoon fresh thyme leaves
1 quart chicken stock or water