Preheat the oven to 200C, fan-forced. Cut the potatoes into 5mm-thick slices. Put the potato and 1 tbs water in a microwave-safe bowl, cover and microwave, gently stirring halfway, for 8-10 mins until the potato is just tender (see Kitchen notes). Drain, then transfer to a 500ml (2 cup) baking dish and season with salt and pepper.
Step 2 — Make sauce
Meanwhile, finely grate the parmesan. Melt 15g butter in a small saucepan over medium-high heat. Add 1 tbs flour and cook, stirring, for 1-2 mins until golden. Gradually whisk in 60ml (¼ cup) milk and 125ml (½ cup) water until smooth. Bring to the boil, then reduce the heat to medium and cook, stirring, for 1 min or until slightly thickened. Remove from the heat.
Step 3 — Bake potato bake
Add the parmesan to the sauce and stir until melted and combined. Taste, then season with salt and pepper. Pour the sauce over the potato in the dish, then bake for 20 mins or until golden.
Step 4 — Cook steaks
Meanwhile, combine the mint and garlic seasoning and 2 tsp olive oil in a large bowl. Add the steaks, season with salt and pepper and turn to coat. Heat a medium frypan over high heat until hot. Reduce the heat to medium-high and cook the steaks, turning regularly, for 4-6 mins for medium-rare, or until cooked to your liking. Remove from the pan and rest for 4 mins.
Step 5 — Make salad and serve up
Cut the apple into thin matchsticks (see Kitchen notes). Combine 2 tsp olive oil and 1 tsp red wine vinegar in a large bowl and season with salt and pepper. Add the apple and rocket and toss to combine. Divide the steaks, potato bake and salad among plates and enjoy!
Step 6 — Kitchen notes
Don't have a microwave? Cook the sliced potato in a saucepan of boiling water until just tender. ~ Here's an easy way to cut the apple into matchsticks: quarter the apple, remove the core, then thinly slice. Stack the slices and cut into matchsticks.