To make the pickled red onions,toast the bay leaf,black pepper,cumin and coriander seeds in a frying pan over medium heat until fragrant (1 to 2 minutes). Place in a heatproof bowl with red onion and garlic.
In a saucepan,bring the cider vinegar,sugar and salt to a simmer,then pour this over onion mix. Allow to cool and place in fridge to pickle overnight.
To make the dressing,bruise the habanero and brown onion using a mortar and pestle. Transfer to a small bowl,add the salt and lime juice and marinate for at least 10 minutes. Add sugar,orange juice,salt and olive oil,and whisk until dissolved. Adjust seasoning and heat to taste.
Preheat barbecue to high. Grill corn,turning regularly,for 15-20 minutes or until lightly charred and tender. Set aside to cool,then cut kernels from cobs.
Layer lettuce,cucumber,corn,pickled onions and coriander on a serving plate. Drizzle with dressing to taste.
Serve as part of Neil Perry's Mexican banquet (recipes here).