Cut the capsicum into small chunks. Finely chop the onion. Crumble 1 stock cube* into a heatproof jug, add 250ml (1 cup) boiling water and ½ tsp sugar and stir to dissolve.
Step 2 — Prep chicken
Cut the chicken into 3cm chunks. Combine the chicken and 1 tsp Spanish seasoning in a bowl and season with salt and pepper.
Step 3 — Brown chicken
Heat 1 tbs olive oil in a medium deep frypan over medium-high heat. Cook the chicken, turning occasionally, for 3-5 mins until browned (the chicken won't be cooked through). Remove with a slotted spoon.
Step 4 — Start paella
Heat the same pan over medium-high heat. Add the capsicum and onion, season with salt and pepper and cook, stirring regularly, for 3 mins or until starting to soften. Add the chicken and any resting juices, tomatoes, stock and remaining Spanish seasoning, stir to combine, then bring to a simmer.
Step 5 — Cook rice
Stir the rice into the chicken mixture. Reduce the heat to medium-low and cook, covered, for 12 mins (the rice won't be fully cooked).
Step 6 — Finish paella and serve
Meanwhile, trim the beans and halve on an angle. Scatter the beans over the paella and cook, covered, for a further 5 mins or until the rice is tender and the liquid is absorbed. Stand, covered, for 5 mins. Taste, then season with salt and pepper. Serve the paella at the table with the aioli.