Easy - for beginners
Preheat your grill to medium/high. Season the steaks with salt and pepper.
Grill the steaks until they are done to your liking. Take the steaks off the grill and allow them to rest on a plate tented with foil.
In a saucepan combine half of the butter, shallots and mushrooms over medium heat. Cook until the shallots are translucent.
Add the wine and lemon juice and cook for another 3 minutes until the wine is reduced by half.
Add any juices from the reserved steaks, cream and tarragon. Cook for another minute.
Add the last bit of butter and cook until it has melted into the sauce.
Taste the sauce and season it with salt and pepper.
Serve sauce, spooned over each steak.