In a large microwave proof bowl, cover bulghar wheat with stock. Cover with cling film and microwave on High for 4 mins. Set aside, covered; it will absorb the stock within another 5 mins. Make a dressing with spice mix, lemon zest and juice and olive oil, then season to taste. Add the onion, chickpeas, peppers and coriander, toss through the cooked bulghar wheat and serve warm or cold.