Adjust rack to top position and preheat oven to 425 degrees. Wash and dry produce.

Peel and dice potatoes into ½-inch pieces. Peel garlic. Trim and halve Brussels sprouts lengthwise. Halve, peel, and thinly slice shallot. Zest orange until you have ½ tsp (1 tsp for 4 servings); halve orange. Pick half the sage leaves from stems (all the leaves for 4); thinly slice leaves until you have 1 tsp (2 tsp for 4). Roughly chop dried cranberries.

Place potatoes and garlic in a medium pot with enough salted water to cover by 2 inches. Bring to a boil and cook until tender, 15-18 minutes.

Reserve ¼ cup potato cooking liquid (½ cup for 4 servings), then drain and return potatoes and garlic to pot.

Add 2 TBSP butter (4 TBSP for 4). Mash with a potato masher or fork until smooth, adding splashes of reserved potato cooking liquid as needed. Season with salt and pepper to taste. Keep covered off heat until ready to serve.

While potatoes cook, toss Brussels sprouts and shallot on a baking sheet with a drizzle of oil, salt, and pepper. Roast on top rack until golden brown and tender, 15-20 minutes.

Meanwhile, squeeze juice from the orange into a small, preferably nonstick, pan (medium pan for 4 servings) over low heat. Stir in stock concentrate, vinegar, ¼ cup water, and 1½ TBSP sugar (½ cup water and 3 TBSP sugar for 4). Whisk to combine.

Increase heat under pan to medium. Add 1 TBSP butter (2 TBSP for 4). Bring mixture to a simmer. Once butter has melted, whisk to combine.

Cook, stirring frequently, until sauce has reduced by about two-thirds and coats the back of a spoon, 10-12 minutes. TIP: During the last 2-3 minutes of cooking, make sure to stir the sauce constantly, because it will thicken rapidly. If it seems too thick, add a splash of water.

While gastrique cooks, in a small heatproof bowl (medium bowl for 4 servings), combine orange zest, sage, and dried cranberries.

Once orange gastrique has reduced, turn off heat and carefully transfer to bowl with cranberry mixture. Stir to combine and set aside. Wash out pan.

Pat scallops* dry with paper towels and season all over with salt and pepper.

Melt 2 TBSP butter (4 TBSP for 4 servings) in pan used for gastrique over medium-high heat. Once butter is bubbling, add scallops and cook until opaque, browned, and cooked through, 3-5 minutes per side. Remove pan from heat.

Divide mashed potatoes and roasted Brussels sprouts and shallot between plates in separate sections.

Top mashed potatoes with scallops (spoon any extra butter in pan over top). Spoon as much orange-cranberry gastrique as you like over scallops. Serve.