Step 1

For the light chicken stock, combine the backs, wings, feet, onions, celery, carrots, thyme, peppercorns and garlic in a large stockpot and add 6 quarts water

Step 2

Bring to a boil over high heat, then reduce the heat to medium-low

Step 3

Season with salt and simmer, skimming periodically, for 3 hours

Step 4

Strain the stock into another clean large pot or bowl and let cool to room temperature

Step 5

Set aside 3 cups for the Salisbury steak, then divide the rest into quart containers and refrigerate for up to 3 days or freeze for up to 6 months

Step 6

For the mashed potatoes, put the potatoes in a large pot, add cold water to cover by 2 inches and season with 2 tablespoons salt

Step 7

Bring to a boil over high heat and cook until fork-tender, about 25 minutes

Step 8

Drain well and return to the pot over high heat for 1 minute to dry out the potatoes a bit

Step 9

Pass them through a food mill or potato ricer into a large bowl

Step 10

Heat the cream, milk and butter in a large saucepan over medium heat until the butter melts and the liquid is warm, about 5 minutes

Step 11

Add the mixture to the potatoes and mix until combined

Step 12

Add more cream and milk, as needed, if the mashed potatoes seem too dry

Step 13

Season with salt and pepper and keep warm while you prepare the Salisbury steak

Step 14

For the Salisbury steak, line a plate with paper towels

Step 15

Heat 1 tablespoon of the oil in a large cast-iron skillet over medium heat

Step 16

Add the bacon and cook until golden brown and crispy and the fat has rendered, about 8 minutes

Step 17

Leaving behind the fat, use a slotted spoon to remove the bacon to the paper towels to drain

Step 18

Heat the rendered bacon fat over high heat until shimmering

Step 19

Add the onion and cook until soft, about 4 minutes

Step 20

Add the garlic and cook for 1 minute longer

Step 21

Transfer the mixture, along with the fat, to a large bowl and let cool slightly

Step 22

Line a sheet pan with parchment paper

Step 23

Add the egg and chipotle to the cooled onion-garlic mixture and mix until combined

Step 24

Add the meat and the panko, season with salt and pepper and gently mix to combine

Step 25

Divide the meat mixture into 4 equal portions and form each portion into an oval patty about 1 inch thick

Step 26

Place the patties on the prepared sheet pan, cover and refrigerate for at least 30 minutes and up to 12 hours

Step 27

While the meat is chilling, heat 1 tablespoon of the oil and the butter in a large high-sided sauté pan over high heat until shimmering

Step 28

Add the mushrooms and cook until golden brown and their liquid has evaporated, about 8 minutes

Step 29

Sprinkle the flour over the mushrooms and cook, stirring constantly, until the flour turns a light golden brown, about 2 minutes

Step 30

Stir in the wine and cook until reduced by half, about 5 minutes

Step 31

Stir in the stock, thyme and bacon and bring to a boil

Step 32

Reduce the heat to medium and cook until the mushroom gravy begins to thicken and the flour taste cooks out, about 8 minutes

Step 33

When ready to cook the Salisbury steaks, heat the remaining 2 tablespoons oil in a large cast-iron skillet over high heat until shimmering

Step 34

Add the patties and cook until golden brown on both sides, about 4 minutes per side

Step 35

Carefully transfer the patties to the gravy and cook, spooning the gravy over them occasionally, until the meat is cooked through and tender, about 30 minutes

Step 36

Serve the Salisbury steaks with mashed potatoes and spoon the gravy over both