Step 1 Place potatoes and corn in a large saucepan and cover with cold water. Cook for 10 minutes, or until just tender, then drain.
Step 2 Press potatoes lightly with a masher to slightly flatten. Spray a large grill pan with cooking oil and set over medium heat. Cook potatoes for 10 minutes, or until crisp and golden.
Step 3 Meanwhile, spray another large grill pan with cooking oil. Cook corn and steak for 5–7 minutes, or until corn is charred and steak is done to your liking.
Step 4 Meanwhile, mix nuts, garlic, parsley and lemon zest in a small bowl to make gremolata. Top steak with gremolata. Serve with corn, potato and baby spinach.