Wash and dry all produce. Preheat broiler to high. Peel potatoes, then cut into 1/2-inch cubes. Place in a medium pot with enough salted water to cover by 1 inch. Bring to a boil and cook until easily pierced by a knife, 10-15 minutes. Drain thoroughly and return to pot.

While potatoes cook, trim woody bottom ends from asparagus. Pick thyme leaves from sprigs until you have 1 tsp; reserve remaining sprigs. Finely chop chives. Cut lemon into wedges. Pat steak dry with a paper towel. Season all over with salt and pepper.

Add 1 cup milk (we sent more) to a small pot along with reserved thyme sprigs. Bring to a gentle simmer over medium heat, then reduce heat to lowest setting and keep warm until ready to use. TIP: Keep an eye on the milk as it’s heating up. It can boil over if it gets too hot.

Heat a drizzle of olive oil in a large pan over medium-high heat. Add steak to pan and cook until browned on both sides but not yet fully cooked, 2-4 minutes. Pour out any excess grease in pan. Reduce heat to low and add butter. Spoon butter over steak as it melts; continue until steak is cooked to desired doneness, 1-3 additional minutes. Transfer steak to a plate and let rest. Remove pan from heat, keeping butter and steak juices in pan.

Toss asparagus on a baking sheet with a large drizzle of olive oil. Season with salt and pepper. Place under broiler and broil until tender and browned, 4-7 minutes. Remove thyme sprigs from milk. Add 1/4 cup milk to potatoes in pot. Mash with a potato masher until smooth, adding more milk as needed to create a creamy consistency. Season with salt and pepper. Stir in reserved thyme leaves.

Slice steak against the grain. Divide asparagus and potatoes between plates, then top with steak. Squeeze a bit of lemon over asparagus. Spoon butter and juices from pan over steak. Garnish with chives and serve with any remaining lemon on the side for squeezing over.