Step 1
Whisk flour and baking powder together in a bowl. Make a well in the centre. Whisk in stock, egg and mirin. Stir in shallot. Set aside.
Step 2
Halve asparagus. Slice stem ends in half lengthways, if thick. Place in a heatproof bowl. Pour over boiling water to cover. Stand for 1 minute. Drain well.
Step 3
Meanwhile, stir-fry the bacon in a wok over medium-high heat for 3 minutes or until crisp. Stir through the batter.
Step 4
Wipe wok clean. Heat 1 tsp of the oil over medium-high heat. Arrange one-quarter of asparagus on base of wok. Pour over one-quarter of the batter mixture. Cook for 2 minutes or until bubbles appear. Use a spatula to carefully turn over. Cook for 1 minute. Transfer to a plate. Repeat with remaining oil, asparagus and batter mixture. Drizzle with mayo and barbecue sauce. Sprinkle with shallot.