Prepare ingredients: Pat the chicken dry and, if one end is thicker, place between two sheets of plastic wrap and gently pound to an even thickness about 1/2 inch (1.3 cm). If your jicama has been pre-sliced into 8 rounds, lay them on a tray and pat dry. Chop 2 tablespoons cilantro; reserve 1 tablespoon for garnish.

Make the marinade/dressing: In a small bowl whisk together 2 tablespoons (30 ml) of the lime juice, 1 teaspoon (5 ml) of the olive oil, 1/2 teaspoon chili powder, 1/2 teaspoon kosher salt, and 1/8 teaspoon black pepper. Reserve this as the chicken marinade.

Marinate the chicken: Place the chicken breasts in a shallow dish or zip-top bag and pour the marinade over them, turning to coat. Let sit at room temperature for 10–15 minutes (or refrigerate up to 1 hour).

While the chicken marinates, make the slaw: In a medium bowl combine the shredded cabbage, the remaining 2 tablespoons (30 ml) lime juice, 1 teaspoon (5 ml) olive oil, 1/8 teaspoon kosher salt, 1/8 teaspoon black pepper, and 1 tablespoon chopped cilantro. Toss well and set aside to let flavors marry.

Preheat grill or grill pan: Heat an outdoor grill or a heavy grill pan over medium-high heat (about 400°F / 200°C). Lightly oil the grill grates or the pan surface (use the remaining 1 teaspoon / 5 ml olive oil on a paper towel to oil grates).

Season and grill jicama rounds: Sprinkle the 8 jicama rounds lightly with 1/8 teaspoon kosher salt and a pinch of black pepper. Place rounds on the hot grill and cook 3–4 minutes per side, until you see grill marks and the rounds are just tender but still hold their shape. Transfer to a plate and keep warm.

Grill the chicken: Remove chicken from the marinade and let excess drip off. Place on the grill and cook 4–6 minutes per side depending on thickness, until an instant-read thermometer inserted in the thickest part reads 165°F (74°C). (If using a grill pan, you may press lightly to get even contact.) Transfer chicken to a cutting board and let rest 5 minutes.

Assemble: Slice the chicken across the grain into 1/4-inch slices. To serve two plates (main portions): place 4 jicama rounds per plate in a loose overlapping row. Pile about 1 cup of the cabbage slaw on each plate (or place slaw atop the jicama if you prefer). Fan sliced chicken over the jicama/slaw. Sprinkle with the remaining 1 tablespoon chopped cilantro and an extra grind of black pepper. Optional: serve with extra lime wedges.

Notes and timing: Total active cook time ~20 minutes, plus 10–15 minutes marinade and 5 minutes resting = approximately 30 minutes. Leftovers: Keep chicken and slaw refrigerated for up to 3 days; jicama rounds are best freshly grilled.