Meatloaf Kebabs with Grilled Potato Salad

Name: Meatloaf Kebabs with Grilled Potato Salad
Ingredients: 1 teaspoon adobo sauce from a can of chipotles in adobo; 1/2 cup plus 2 tablespoons ketchup; 3 tablespoons Worcestershire sauce; Juice of 1 large lemon; 1 pound ground beef chuck; 1 large egg, beaten; 1/4 cup seasoned Italian breadcrumbs; 1/2 medium onion, finely grated; Kosher salt and freshly ground black pepper; 1 pound baby red potatoes, halved; 1 tablespoon extra-virgin olive oil, plus more for brushing; 2 scallions, green parts only, thinly sliced