Garlic Butter Steak & Mushrooms

From Donna Hay's Instant Entertaining cookbook

8 thin sirloin steak ( I used 2 Porterhouse for Ryan)
80g butter, melted
2 cloves garlic, minced
2 tbs olive oil
2 tsp Dijon Mustard
salt and pepper
4 Field mushrooms
baby spinach

Mix butter, garlic, olive oil, Dijon mustard and salt and pepper together. Brush butter mixture onto mushrooms and steaks. Cook steaks in fry pan until browned and cooked, around 4mins. Remove and cook steaks to your desired length, around 8mins for medium. Remove and put any remaining butter mixture into pan to warm up. Place sauteed spinach on plate, top with steak and then mushroom. Pour butter sauce over steak. Serves 4.

EASE: 5/5. Not much effort at all. I halved the recipe.
Prep time: 5mins. To make butter mixture and wash spinach/peel mushrooms.
Cooking time: 15mins. The spinach took around 2mins to wilt. I just sauteed it in some butter and oil with lots of minced garlic and some salt and pepper. The mushrooms took 5mins (my pan was not hot enough) and the steak took 8mins for medium.
TOTAL: 20mins. Everything goes in the same pan after each other, and all cook quickly.
TASTE: 4.5/5. I LOVED the flavour of the mushrooms with the butter sauce; really tasty. The spinach was beautiful (I always do it the same) and Ryan said the steak was great. I will be using the butter mixture for all mushrooms I quickly fry in the pan (I used Swiss Brown - couldn't get Field). I also used two Porterhouse steaks.
Would I make it again: Yes. Super quick - on the table in 20mins and full of flavour. Ryan did initailly complain that I didn't make mash with it - but he couldn't even finish his plate, so it's not needed.