01 - In a mixing bowl, whisk together the olive oil, Vegemite, honey, minced garlic, smoked paprika, and a generous pinch of 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 - Heat 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 outside and cooked through to an internal temperature of 165°F. Transfer to a cutting board and let 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 fully blended. Set aside.
05 - Warm the flour 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 warm tortilla flat on a work surface. Spread a generous spoonful of the Dijon sauce along the center. Layer with baby spinach, sliced cucumber, julienned carrot, red onion, and sliced 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.