Prep the ingredients per the instructions above.
Assemble the salad ingredients into a bowl. Wait to dress the salad until ready to serve.
Cook the potatoes: Place potatoes in a pot; cover with cold water and set over high heat. Once boiling, turn the heat down to a simmer.
Season the steaks generously on both sides with steak seasoning.
For the potatoes: In a small saucepan, melt the butter. Then stir in the cream until warmed and then remove from the heat and set aside.
Preheat a cast iron skillet or heavy-bottom non-stick pan over medium heat. Once hot, add the oil.
Place the steak into the pan and sear well on all sides to get a nice char. Once nicely charred, lower the heat as needed so the steak cooks without burning the outside.
Check the potatoes by inserting a fork into them; once the fork slides in and out with ease, take off the heat and strain out all of the water. Mash the potatoes with a fork or masher. Slowly add in the cream and butter mixture and mix until fully incorporated. Mix in the scallions. Season with salt and pepper to taste. Cover tightly to keep warm.
Continue cooking the steaks until they reach your desired temperature using a thermometer (see below).If a more well-done temperature is preferred, it is recommended to finish the steak in a 350°F (176°C) oven so that it cooks evenly and the outside doesn't burn. Remove the steak from the pan and set it aside to rest for 5 minnutes. Deglaze the pan with broth, scraping up the browned bits from the bottom of the pan. Then add the thyme and butter. Once everything is combined remove the pan from the heat.
Preheat the broiler on low. While the steak is resting, make the bread: Spread the butter and garlic onto the bread. Broil until golden brown.
Mix the sparkling water and lemon. Dress the salad.
Slice the steak against the grain and drizzle the pan jus over top. Serve with mashed potatoes, salad, bread, and spritzer.