01 - In a mixing bowl, whisk together the olive oil, Vegemite, honey, minced garlic, smoked paprika, salt, and pepper until smooth and well combined.
02 - Coat the chicken pieces evenly with the Vegemite marinade, ensuring all surfaces are covered. Allow to marinate for at least 15 minutes at room temperature, or cover and refrigerate for up to 4 hours for deeper flavor penetration.
03 - Preheat a grill pan or barbecue over medium-high heat. Grill the marinated chicken for 6 to 7 minutes per side until nicely charred on the exterior and cooked through to an internal temperature of 165°F. Transfer to a plate and rest for 5 minutes before slicing thinly against the grain.
04 - In a small bowl, stir together the mayonnaise, lemon juice, and Dijon mustard until smooth and creamy. Set aside.
05 - Warm the flour tortillas or flatbreads in a dry skillet over medium heat for about 30 seconds per side, or microwave in 10-second intervals until pliable and easy to fold.
06 - Lay each tortilla flat on a work surface. Spread a generous spoonful of the sauce along the center. Layer with baby spinach, sliced cucumber, julienned carrot, red onion, and slices of the charred chicken.
07 - Fold in the sides of each tortilla, then roll up tightly from the bottom to form a secure wrap. Slice in half diagonally if desired and serve immediately.