In a bowl, mix together 1 tsp Dijon mustard, 2 cloves minced garlic, 1 diced red chilli, 2 TBSP chopped Italian parsley, 1 tsp fresh thyme, 1 tsp Worcestershire sauce, 1 tsp smoked paprika, 1/2 tsp chilli flakes, 120g unsalted butter, the juice of half a lemon, and 1/2 tsp salt.
Once combined, spoon the cowboy butter into the base of the BBQ flat mushrooms.
Set your BBQ to high and preheat.
Place the mushrooms on the grill upside down, allowing the cowboy butter to melt and cook inside the mushroom.
After a few minutes, place your seasoned steak on the BBQ alongside the mushrooms and grill for 3-4 minutes on each side.
Once everything is cooked, remove from the grill and rest for a couple of minutes.
Serve the cowboy butter mushrooms directly on top of the steaks.
Slice and enjoy!
