Trim the ends off the Brussels sprouts and cut them in half. Reserve in a large mixing bowl.
In a large glass measuring cup, add olive oil, balsamic vinegar, lemon juice, garlic, salt, pepper, thyme and rosemary; mix with a flat whisk until very well combined and pour over reserved sprout. Mix to coat evenly and spread in a single layer in a broiler pan.
Place in the oven and bake for 20-25 minutes, turning once or twice, until the sprouts are tender and golden.