For the marinade:
1 tablespoon good-quality balsamic vinegar
2 tablespoons olive oil
2 cloves garlic, crushed into a paste
Handful of finely chopped fresh herbs (we used parsley and tarragon)
1 teaspoon salt
1/2 teaspoon pepper
Skewer ingredients:
12-15 small new potatoes
1 pint cherry or grape tomatoes, rinsed
1 red or sweet onion, cut into wedges (leave ends intact so they hold together)
2 zucchini, rinsed and cut into 1/4" rounds
1 red or yellow bell pepper, cored and cut into 1" pieces
Make the marinade: Whisk together all marinade ingredients in a nonreactive bowl and set aside.
Parboil the potatoes: Add potatoes to a pot and cover with cold water and generous pinch of salt. Bring to a boil and cook for 8-10 minutes; you'll want the potatoes tender enough to be pierced with a fork but not falling apart. Drain and set aside to cool. Once the potatoes have cooled, slice each potato in half lengthwise.
White the potatoes are coking soak 10-12 wooden skewers in a plate of water. this will prevent them from burning on the grill. Or you can use metal skewers.
Add all veggies and potatoes to a large mixing bowl. Add marinade and toss gently with your (clean) hands to combine.
Preheat your grill or a grill pan to medium-high.
While grill is heating up, thread potatoes and vegetables onto skewers, distributing evenly. Continue until all vegetables are used; pour any remaining marinade over skewers.
Grill skewers for 8-10 minutes, flipping once in the middle of cooking. You want a light char on the vegetables and the tomatoes should just be starting to burst. Remove from heat and let cool for a few minutes before serving.