Heat the oven to 220C/200C fan/gas 7. Chop the broccoli stalks, leaving the florets whole, and put all of it in a large bowl. Add the pak choi, red onions, peppers, carrots, chickpeas (patted dry with kitchen paper), oil, 3 tbsp of the teriyaki sauce and the ginger. Toss until everything is coated and season lightly. Tip onto a large non-stick baking sheet in a single even layer, using two trays if needed.
Bake the veg for 35-40 mins, tossing halfway through until starting to brown. When there is 5 mins of cooking time left, heat up the rice. Divide the rice between the bowls and top with the roasted veg. Drizzle over the reserved teriyaki sauce and scatter with the spring onions and sesame seeds.
