1/2 cup balsamic vinegar
2 tablespoons honey
1 tablespoon whole grain mustard
3 cloves garlic, minced
salt
pepper
14 ounces sirloin, cut into 1-inch cubes
Tomato Marinade:
2 cups whole grape tomatoes
1/3 cup olive oil
2 tablespoons fresh rosemary (stems removed), chopped
Potatoes:
1 1/2 pounds baby potatoes
6 metal or wooden skewers
Preheat grill to medium heat and if using wooden skewers, place them in water to soak. Marinade: In a large bowl, whisk together balsamic vinegar, honey, mustard, and garlic. Season to taste with salt and pepper. Add the cubed steak and toss to coat. Cover and refrigerate for 20 minutes (up to overnight) so the steak can marinate. Tomato Marinade: In another bowl, add the tomatoes, olive oil, and rosemary. Set aside. Potatoes: Place the potatoes in a large pan and add enough water to cover all of the potatoes by 1 inch. Bring the water to a boil and cook potatoes until they barely fork-tender, about 8-10 minutes. (They will be grilled later, so do not need to be cooked through.) Drain and set aside. Assembly: Grab a skewer and start with potato, then add steak, then a tomato. Repeat two more times and end with a potato. Lightly oil the grill and set the kebabs over the heat. Grill for about 5 minutes on each side, or 10 minutes total. (You don't want to overcook the steak.)