Preheat the oven to 400°F. Line a baking sheet with parchment paper.

Place steak into a shallow dish, rub the Dijon mustard and 1½ teaspoon of oil into the steak. Leave to marinate for at least 10 minutes in the fridge.

Prepare quinoa according to packet instructions.

Place asparagus onto the baking sheet and drizzle over ½ teaspoon of oil and the balsamic vinegar. Toss to coat. Bake for 10 to 15 minutes, or until asparagus are golden brown.

Heat a non-stick skillet to medium-high. Once hot, cook steak for 3 to 4 minutes each side for medium, or until cooked to your liking. Remove the steak and rest under foil for a few minutes.

Thinly slice the steak. Divide asparagus, steak and quinoa between two serving plates. Drizzle over any remaining juices from the pan.