Step 1 Preheat oven to 200°C. Spray a 6-cup baking dish with oil. Place a third of the Brussels sprouts in a single layer in baking dish. Layer over a third of the potatoes. Continue alternating layers until all vegetables are used. Pour milk over top layer.

Step 2 Bake for 35 minutes. Sprinkle with parmesan and cook for 5 more minutes, or until potatoes are tender and milk has been absorbed.

Step 3 Meanwhile, spray a large frying pan with oil, place over medium-high heat and cook steaks to your liking (about 8–10 minutes for medium). Serve with gratin and salad.