01 - In a mixing bowl, whisk together olive oil, Vegemite, honey, minced garlic, smoked paprika, salt, and pepper until well combined.
02 - Coat chicken pieces evenly with the Vegemite marinade. Let marinate for at least 15 minutes at room temperature, or cover and refrigerate up to 4 hours for deeper flavor penetration.
03 - Heat a grill pan or barbecue over medium-high heat. Grill chicken for 6–7 minutes per side until nicely charred and cooked through (internal temperature reaches 165°F). Let rest for 5 minutes, then slice thinly against the grain.
04 - In a small bowl, combine mayonnaise, lemon juice, and Dijon mustard. Stir until smooth and set aside.
05 - Warm tortillas or flatbreads in a dry skillet over medium heat or microwave for 15–20 seconds until pliable.
06 - Lay out each tortilla flat. Spread a generous spoonful of sauce along the center. Layer with spinach, cucumber slices, julienned carrot, red onion, and sliced charred chicken.
07 - Fold in the sides of each tortilla, then roll up tightly from the bottom. Slice in half on a diagonal and serve immediately.