1 tbsp plain flour
½ cup beer
1 tsp Dijon mustard
1 cup grated tasty cheese
1 tbsp thyme leaves, optional
4 thick scotch fillet or porterhouse steaks
4 large mushrooms
oil for deep frying
3 large potatoes, peeled, very thinly sliced
1 Melt butter in a small saucepan over medium heat. Add flour and stir until well combined. Cook for 1 minute. Remove from heat. Slowly add beer, whisking constantly until well combined. Stir in mustard. Return to heat and bring to the boil, stirring constantly. Add ¾ cup cheese; stir until melted. Remove from heat; stir in thyme.
2 Preheat chargrill over medium-high heat. Season steaks on both sides with salt and pepper. Add 2 steaks to chargrill. Cook for 3-4 minutes each side for rare, or until cooked to your liking. Transfer to a plate. Repeat with remaining steaks.
3 Preheat grill to high. Add mushrooms to chargrill and cook for 3 minutes on each side or until tender. Transfer to a tray. Spoon sauce onto mushrooms. Sprinkle over remaining cheese. Place under grill for 2 minutes or until cheese has melted and is golden.
4 Scrunch baking paper and place on baking tray. Half fill a saucepan with oil and heat over high heat. Add ⅓ chips to pan. Cook for 4 minutes or until golden and crisp. Transfer to prepared tray. Repeat with remaining chips, in batches. Serve steak topped with a rarebit mushroom and chips on the side.