Preheat the fan oven to 180°C. Toast the almonds for 10 minutes on a tray until golden-brown, allow to cool a little and chop roughly. Mix all of the spices from the cinnamon to the pepper in a bowl. Heat the coconut oil in a tagine or a wide-bottomed, deep frying pan on a medium heat, lightly fry the garlic and onion, add all of the spices at once and fry together for 1–2 minutes, stirring constantly. Add the vegetables and continue to fry for a couple more minutes. Add the water, cinnamon sticks, honey, almond paste and plums, stir well, cover, and simmer on a low to medium heat for 35-45 minutes. Stir occasionally and add a little more water if necessary.
Boil the water (without salt!). Add the barley and simmer over a medium heat for approx. 30 mins. Remove the pan from the hob, cover, and allow the barley to stand for another 10-15 mins. (to ensure the barley is ready at the same time as the tagine). Mix the almond paste, lime juice, orange juice and coriander into the cooked barley, season.
Halve the avocado, remove the stone, peel and cut into thin slices, drizzle over a little lemon juice, and season with salt and pepper.
Stir half of the toasted, chopped almonds into the tagine. Serve some tagine onto the plate, place the barley on top, then garnish with the rest of the chopped almonds, the fresh herbs, and the avocado slices if desired.