Step 1

Marinate the meat: Combine the chicken, lime juice, 2 tablespoons of the oil, paprika, cumin, and chili powder a medium bowl and toss to thoroughly coat the chicken with the spices. Set this aside while you prepare the vegetables.

Step 2

Season the vegetables: Combine the onion, bell pepper, and zucchini in a large bowl. Drizzle with the remaining 1 tablespoon of oil, season with salt and pepper, and toss to coat.

Step 3

Build the skewers: Line a rimmed baking sheet with parchment paper. Thread the meat onto 8 of the skewers, about 6 cubes per skewer. Lay the skewers on the baking sheet. Cover the skewers completely with a second sheet of parchment. Thread the vegetables onto the remaining 8 skewers, alternating between 1 piece of bell pepper, 3 slices of onion, and 1 piece of zucchini that you skewer through the skin. Place the skewers on the second sheet of parchment.

Step 4

Freeze and store: Freeze until solid, at least 3 hours or overnight. Wrap the entire baking sheet tightly in aluminum foil, or transfer the skewers to gallon-sized freezer zip-top bags, trimming the skewers if needed. Freeze for up to 3 months.

Step 5

Grill: Heat an outdoor grill to medium-high (about 400°F). Place the frozen skewers on the grill (do in 2 batches if needed), cover the grill, and cook undisturbed until grill marks appear on the chicken, about 3 minutes. Using tongs, rotate the skewers a quarter turn, cover the grill, and grill 3 minutes. Continue rotating the skewers a quarter turn every 2 to 3 minutes until the vegetables are crisp-tender and the chicken is cooked through, 12 to 15 minutes total. Remove to a platter and rest for 3 minutes before serving.