Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 425 degrees. Wash and dry produce.

Cut potatoes into ½-inch-thick wedges. Trim, peel, and cut carrots on a diagonal into ¼-inch-thick pieces. Halve, peel, and thinly slice shallot.

Toss potatoes on one side of a baking sheet with a drizzle of olive oil, salt, and pepper (for 4 servings, spread out across entire sheet).

Roast on top rack for 5 minutes (you’ll add more to the sheet then).

Meanwhile, in a medium bowl, soak panko with 1 TBSP water (2 TBSP for 4 servings) and stock concentrate until liquid has absorbed. Add beef*, ½ tsp salt (1 tsp for 4), and pepper; mix to combine.

Form beef mixture into two ½-inch-thick rounds (four rounds for 4). Reserve half the cheddar for topping; divide remaining cheddar between the centers of each round. Gently fold meat around cheese, shaping and sealing to create 1-inch-thick loaves.

Once potatoes have roasted 5 minutes, remove sheet from oven. Add meatloaves to opposite side of sheet. (For 4 servings, leave potatoes roasting; add meatloaves to a second sheet and roast on middle rack.)

Roast on top rack until potatoes are browned and tender and meatloaves are cooked through, 17-20 minutes more.

In the last 2 minutes of roasting, top meatloaves with reserved cheddar. Return to oven until cheese melts.

Heat a drizzle of oil in a large, heavy-bottomed pan over medium-high heat. Add carrots and a pinch of salt and pepper; cook, stirring occasionally, until browned and softened, 5-7 minutes. TIP: If carrots begin to brown too quickly, add a few splashes of water.

Turn off heat; transfer carrots to a plate. Wipe out pan.

In a small bowl, toss shallot with flour and a pinch of salt and pepper.

In pan used for carrots, heat a ⅓-inch layer of oil over medium heat. Once oil is hot enough that a pinch of flour sizzles immediately when added to the pan, add coated shallot. Cook, stirring occasionally, until golden brown, 3-5 minutes.

Using a slotted spoon, transfer shallot to a paper-towel-lined plate.

Meanwhile, in a separate small bowl, combine ketchup and mayonnaise. Stir in water 1 tsp at a time until mixture reaches a drizzling consistency. Season with salt and pepper.

Slice meatloaves crosswise if desired.

Divide meatloaves, potato wedges, and carrots between plates. Drizzle meatloaves with some of the special sauce. Serve remaining sauce on the side with potatoes for dipping. Garnish meatloaves with crispy shallot and serve.