Steak:
Preheat your oven to 350 degrees F. Place the steaks onto a baking sheet and bake in the oven.

Rare: bake at 350 degrees for 8 minutes
Medium Rare: bake at 350 degrees for 10 minutes
Medium: bake at 350 degrees for 12 minutes
Medium Well: bake at 350 degrees for 14 minutes
Well-Done: bake at 350 degrees for 18 minutes

Use a thermometer to check the internal temperature:
Rare 100 degrees
Medium Rare 110 degrees
Medium 120°
Medium Well 135 degrees
Well-Done 155 degrees

Before serving, let the steaks rest for 3-4 minutes.

Prawns:
Bake at 350 degrees to an internal temperature of 140 degrees (should be about 8-12 minutes)

Potatoes and Asparagus:
Bake at 350 degrees for 12 minutes. At 6 minutes, pull out and mix the potatoes, and finish baking for 6 more minutes.