01 - In a mixing bowl, whisk together the olive oil, Vegemite, honey, minced garlic, smoked paprika, salt, and pepper until well combined into a smooth glaze.
02 - Coat the chicken pieces evenly with the Vegemite marinade, ensuring full coverage. 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 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, fresh lemon juice, and Dijon mustard until smooth and well blended. Set aside.
05 - Warm the tortillas or flatbreads in a dry skillet over medium heat for about 30 seconds per side, or microwave briefly 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 on a diagonal and serve immediately.