Wash and dry all produce. Adjust rack to middle position and preheat oven to 425 degrees. Cut potatoes into 1/2-inch cubes. Place in a medium pot with a pinch of salt and enough water to cover by 1 inch. Bring to a boil and cook until easily pierced by a knife, about 12 minutes. Drain, then return to pot.

Trim woody bottom ends from asparagus. Mince chives. Cut lemon into wedges. Pat pork dry with a paper towel. Heat a large drizzle of oil in a large pan over medium-high heat. Season pork with salt, pepper, and half the flour. Cook in pan until just browned, about 2 minutes per side. Transfer pork to a baking sheet, placing toward one side.

Toss asparagus with a large drizzle of oil on other side of same baking sheet. Season with salt and pepper. Bake in oven until asparagus starts to brown and pork reaches desired doneness, 7-10 minutes. (TIP: If pork is done before asparagus, remove from sheet and let asparagus finish.) Let pork rest on a plate for 5 minutes after it’s done.

Pour out any grease in pan used for pork. Add 1 TBSP butter and remaining flour to same pan over medium heat. Cook, stirring, until butter is melted and a pasty mixture has formed, 1-2 minutes. Stir in demi-glace, thyme sprigs, and 2/3 cup water. Simmer until thickened, about 2 minutes. Add another 1 TBSP butter, stirring to melt. Season with salt and pepper. Remove pan from heat. Stir in a squeeze of lemon.

After draining and returning potatoes to pot, add 1/2 cup milk (we sent more) and chives (add the chives to taste—you may not use all). Mash with potato masher or fork until smooth. Season with salt and pepper. TIP: Add more milk, if necessary, to give potatoes a creamy consistency.

Divide potatoes between plates. Stir any juices released by pork into gravy in pan. Divide pork and asparagus between plates. Remove and discard thyme sprigs from gravy, then spoon gravy over everything. Serve with lemon wedges on the side.