Start potatoes: Peel and cube 3 medium potatoes. Place in a pot, cover with cold water, add 1 tsp salt. Bring to boil, then reduce to simmer for 15-20 minutes until fork-tender.

Prep and season steak: Pat 1 ribeye steak (10-12 oz) completely dry with paper towels. Season generously on both sides with salt and black pepper. Let sit at room temperature while potatoes cook.

Sear the steak: Heat 1 tbsp oil in a cast iron or heavy skillet over high heat until smoking. Add steak and sear 3-4 minutes per side for medium-rare (adjust for desired doneness). Add 2 tbsp butter and 3 garlic cloves (smashed) to pan during last minute, spooning melted butter over steak.

Make mashed potatoes: Drain cooked potatoes. Return to pot and mash with ¼ cup milk, 2 tbsp butter, and 2 minced garlic cloves (or use the pan-roasted garlic from steak). Season with salt and pepper to taste.

Rest and serve: Transfer steak to cutting board, tent with foil, and let rest 5 minutes. Slice against the grain. Serve steak slices over mashed potatoes, drizzled with pan butter sauce. Garnish with fresh thyme or parsley if available.