Preheat the oven to 180 °C.
Separately steam the cauliflower, broccoli and sweet potato cubes until they are al dente (cooked but still firm to the bite). Place in a bowl, add half the olive oil and half the crushed garlic, then season to taste with mixed herbs, origanum, and BBQ spice. Toss to coat and set aside.
Heat the remaining 15ml olive oil in a pan and stir-fry the onion and sweet pimiento until just soft. Add the soy sauce and the remaining 5ml garlic, then stir in the baby spinach. Set aside.
Prepare the couscous as per the instructions on the box and set aside to cool slightly. Brush the inside of a big oven-proof dish with a little oil, and then brush again with the beaten egg yolk - this will help the couscous layer form a crust.
In a saucepan, mix together the almond milk and the contents of the sachet of KNORR Peri-Peri Sauce. Bring to the boil, stirring. The sauce shouldn't be too thick, so add a little water if necessary.
To assemble the dish, tip the couscous into the baking dish and press down firmly and evenly to create the bottom layer. Spread half the onion/spinach mixture on top. Top with all the cauliflower, broccoli and sweet potato. Spread the remaining onion mixture on top, then pour the prepared Peri-Peri Sauce all over the dish.
Sprinkle the mozzarella cheese on top and at bake at 180°C for 10 minutes, or until the cheese is golden brown and bubbling.
Garnish with fresh coriander and serve hot.