Marinating juicy pieces of lamb in a flavorful combination of buttermilk, garlic, and dill ensures tender meat with a delicate Mediterranean flair that pairs beautifully with grilled zucchini and squash.
Combine buttermilk, garlic, dill, and 1 teaspoon salt and 1/2 teaspoon pepper. Set aside 1/4 cup of marinade. Reserve and refrigerate about 1/4 cup of marinade. Transfer remaining marinade to a zip-top bag and add lamb and toss to coat. Refrigerate 8 hours (or up to overnight).
Heat a grill or grill pan to medium-high. Clean and lightly oil hot grill. Thread some skewers with lamb, others with zucchini, and others with summer squash. Season with salt and pepper. Grill lamb skewers for 9 to 12 minutes and zucchini and squash skewers for 12 to 15 minutes, turning all skewers frequently and brushing with reserved marinade.