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, ensuring thorough coverage. Allow to 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 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 cutting board and rest for 5 minutes before slicing 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 in the microwave for 15 to 20 seconds until pliable and easy to roll.
06 - Lay each tortilla flat on a work surface. Spread a generous spoonful of the sauce along the center. Layer with spinach leaves, cucumber slices, julienned carrot, red onion, and sliced charred chicken.
07 - Fold in the sides of each tortilla and roll up tightly from the bottom. Slice diagonally in half and serve immediately.