1. Put garlic-flavored oil and rosemary into a nonstick, thick-bottomed wok (or wide, heavy pan) that has a lid; warm over low to medium heat, letting rosemary sizzle fragrantly, for 30 seconds.
2. Add cherry (or grape) tomatoes; cook, stirring gently, until tomatoes start softening and oozing their viscous juices, about 1 1/2 minutes.
3. Add vermouth and bring to a bubble. Clamp on lid and cook 1 minute longer.
4. Remove lid and stir in olives. Let bubble uncovered until the juices reduce a little, about 1 minute longer. Stir in most of parsley and season to taste with salt and pepper. Pour into a warmed serving dish and let stand 10 minutes to allow juices to thicken and flavors to mellow.
5. Sprinkle with remaining parsley and serve.