With the water clinging to the Broccolini®, place into a snap lock bag in a single layer. Microwave for 1 minute on High/100%. Carefully drain, pat dry with paper towel, then arrange on a tray. Drizzle over the oil, sprinkle with seasoning, turning to coat.
Preheat the barbecue plate on medium. Add the Broccolini® and lemons cut side down. Barbecue for 4 minutes, turning the Broccolini® often until lightly charred. Then transfer to a tray. Serve with mayonnaise and charred lemon.