The tahini-yogurt marinade for these skewers works well with all kinds of protein, from chicken and beef to salmon or lamb. It's so good you may want to make extra and set it aside, so you can use some as a dip. And while you're at it, grill some vegetables kebabs, as well! I've included a few ideas below. —EmilyC
In a large bowl, whisk together all of the ingredients until smooth and emulsified. If you’re using Greek or skyr yogurt, you may need to add a bit more extra-virgin olive oil to loosen the marinade.
For the skewers:
In a bowl or plastic zipper-lock bag, combine chicken with half of marinade. Repeat with steak. Cover and refrigerate for at least 2 hours, or up to 24 hours.
Soak wooden skewers in cold water for 30 minutes before grilling.
Remove the chicken and steak from the marinade, letting any excess drip off. Working one protein at a time, thread 5 or 6 cubes on each wooden skewer. (Tip: thread the cubes on 2 skewers so the pieces don’t flip over on the grill when you turn them). Let stand at room temperature while the grill heats up.
Cut vegetables into bite-sized (abut 2-inch) pieces. (Leave cherry tomatoes and peppadews whole.) Toss vegetables in olive oil to generously coat, and season with kosher salt, to taste. Alternating with squash and cherry tomatoes, thread onto skewers. Repeat with red onion, eggplant, and peppadews or red peppers.
Heat grill to medium-high and brush your grates clean.
Grill each skewer until it reaches your desired degree of doneness (165F° for chicken, 125F° to 130F° for medium-rare steak). This should take about 3 to 5 minutes per side for the steak, zucchini, and eggplant skewers; and about 5 to 7 minutes per side for the chicken skewers.
Remove from the grill and place on a platter; tent with foil to keep warm until all the skewers are complete.