To make the dressing, blend jalapeno, garlic and ginger in a blender until finely chopped. Add lime juice, coriander, honey, balsamic and salt; pulse to blend. With blender running, drizzle in oil until well incorporated.
Preheat the grill. Season steak with salt and black pepper; transfer to a foil-lined tray.
Grill on top shelf until medium-rare, 3 to 4 minutes per side. Let rest for about 10 minutes, then thinly slice against the grain.
Stir together sweetcorn, yellow pepper, red onion, tomato and jalapeno (if using) in a bowl.
Divide lettuce among 4 plates; drizzle each with about 2 tablespoons dressing. Top with slices of steak, then with sweetcorn mixture. Sprinkle crumbled feta and tortilla chips on top.
If you opt to use corn on the cob, grill the cob beside the steak to blacken the kernels; slice off kernels when cool enough to handle.