Finely chop the capsicum. Thinly slice the spring onion on an angle. Crush or finely chop the garlic. Crumble 1 stock cube* into a heatproof jug, add half the tomato paste* and 250ml (1 cup) boiling water and stir to dissolve.
Step 2 — Cook chicken
Put the chicken flat on a board, put your hand on top and halve horizontally into fillets. Season the chicken with salt and pepper. Heat 2 tsp olive oil in a medium deep frypan over medium-high heat. Cook the chicken for 2-4 mins each side until golden and cooked through. Remove from the pan, reserving the pan. Rest for 3 mins.
Step 3 — Prep slaw ingredients
Meanwhile, finely shred the cabbage with a sharp knife or mandoline. Shred the carrot using a julienne peeler or coarsely grate with a box grater.
Step 4 — Start sauce
Heat 1 tbs olive oil in the reserved pan over medium heat. Cook the capsicum and half the spring onion, stirring, for 2-3 mins until tender. Add the garlic and 2 tsp Spanish seasoning* and cook, stirring, for 1 min or until fragrant.
Step 5 — Finish sauce
Stir tomato stock and a pinch of sugar into the capsicum mixture and bring to a simmer. Cook, stirring occasionally, for 6-8 mins until the sauce is thickened. Thinly slice chicken, add to the sauce and stir to combine. Taste, then season with salt and pepper. Remove from heat. Put tortillas on a plate, slightly overlapping, and microwave for 30 secs or until warmed through.
Step 6 — Get ready to serve
While the sauce is cooking, put the aioli and 2 tsp red wine vinegar in a large bowl, season with salt and pepper and stir to combine. Add the cabbage, carrot and remaining spring onion and toss to combine. Divide the tortillas among plates, then fill with the chicken mixture and most of the slaw. Serve with the remaining slaw.