Medium sauté pan or skillet
Read through the entire recipe before getting started. Wash and dry all produce. Mince or grate garlic. Cut potatoes in half, then halve them again and dice into 1" cubes.* Cut cremini mushrooms in HALF. Remove thyme leaves from stem and discard only the tough stems. Keep leaves and tender stems. Remove steak from package; rinse and pat dry.
*We like skin-on, rustic mashed potatoes, but you can peel the potatoes if you prefer.
Place potatoes in medium pot covered by 2" of water over medium heat (about 6 cups); add a pinch of salt. Bring to a boil; cook for 10-14 min until potatoes are soft. Pierce gently with fork to check tenderness. While potatoes are cooking, move on to Step #3. Reserve 1 cup potato water, strain potatoes, and return to pan. Add ½ cup potato water; mash using a potato masher or fork until incorporated. Add the rest of the potato water if mashed potatoes are too thick. Remove from heat, add HALF sour cream and season with a pinch of salt and pepper. Mix until incorporated and soft.
Mix ½ tsp. salt and a pinch of pepper into the spice blend to create a rub. Place steaks in a medium bowl. Drizzle 1 ½ Tbsp. oil and rub with HALF garlic and spice blend on both sides until incorporated. Allow steak to sit for 2-3 min at room temperature.
Pro-tip: While your steak sits, use the time to reserve potato water and check the tenderness of your potatoes by piercing with a fork.
Heat a medium skillet over moderate-high heat. Add steak to pan and allow to sear for about 3 min. Flip and sear the other side for about 3-5 min until cooked to desired doneness. Remove from pan, cover and allow to rest until ready to plate. Do not clean pan.
The USDA recommends cooking beef to an internal temperature of 145ºF.
Add 1 Tsp. oil, cremini mushrooms, remaining HALF garlic and thyme to previously used pan. Cook 2-3 min until beginning to soften. Deglaze pan with ½ cup water and bring to a simmer. Add remaining sour cream, a pinch of salt and pepper. Whisk to incorporate and simmer until reduced by HALF and sauce begins to thicken. Remove from heat.
Note: When simmering sauce, you should see small bubbles on the surface. If not, increase heat.
Divide mashed potatoes between two plates. Place one spice & salt crusted steak on each plate and top with plenty of creamy mushroom sauce. Enjoy!