Preheat the oven to 220C, fan-forced. Line an oven tray with baking paper. Halve the unpeeled potatoes, quartering any large ones. Put on the lined tray, drizzle with 2 tsp olive oil and toss to coat. Roast for 20-25 mins until golden and tender.
Step 2 — Fry capers
Meanwhile, drain the capers and pat dry with paper towel. Heat 2 tsp olive oil in a small frypan over high heat. Carefully add the capers to the pan and cook, stirring, for 3-5 mins until crisp. Remove from the pan and drain on paper towel.
Step 3 — Chargrill zucchini
Heat a chargrill pan over medium-high heat until hot. Peel the zucchini into ribbons with a vegetable peeler. Drizzle the zucchini with 2 tsp olive oil, season with salt and pepper and toss to coat. Chargrill the zucchini, in batches, for 1 min each side or until lightly charred. Remove from the pan.
Step 4 — Chargrill steaks
Heat the chargrill pan over high heat until hot (it's important to have the pan very hot before adding the beef, otherwise it may stew slightly and become tough). Drizzle the steaks with 2 tsp olive oil and season with salt and pepper. Reduce heat to medium-high and cook steaks for 2-3 mins each side for medium-rare, or until cooked to your liking. Remove from pan and rest for 3 mins.
Step 5 — Make salad
Put 2 tsp extra virgin olive oil, 1 tsp balsamic vinegar and 1 tsp wholegrain mustard in a large bowl. Season with salt and pepper and whisk to combine. Add the salad leaves and zucchini to the dressing and toss to combine.
Step 6 — Season potato and serve
Scatter the roast potato with the barbecue seasoning and toss to coat. Divide the steaks, potato and salad among plates and scatter the capers over the salad. Serve with the burger sauce.