For the beef bourguignon

Cover the cubed rib eye with the wine and marinate for 3 hours. Reserving the wine in a small pot, drain the meat, pat dry, and season well with salt and pepper. Bring the wine to a simmer; reduce by half and set aside. Tie sachet ingredients into a cheesecloth square and set aside.

Pour the olive oil into a large Dutch oven or heavy-bottomed pot and cook over high heat. When the oil starts to smoke, add the rib eye and sear on all sides. Transfer the meat with a slotted spoon to a plate and drain all but approximately 3 tablespoons of fat from the pot. Reduce heat to medium and add the vegetables. Cook, stirring, until the onions begin to soften, about 4 minutes.

Add the tomato paste and cook, stirring for another 2 minutes. Return the meat to the pot and sprinkle in the flour, covering all the ingredients. Cook, stirring, until the flour is dissolved. Add the reduced wine, stir, and bring to a simmer, then add the veal stock and sachet, stir, and bring to a simmer again. Cover and cook at a very low simmer for 2 hours, or until the meat is fork-tender. Make the mashed potatoes while the meat is braising.

For the mashed potatoes

Place the potatoes in a pot and cover with water. Add the salt and bring to a boil. Simmer for 12 minutes, or until the potatoes are cooked through.

In another small pot, bring the cream, garlic, thyme, and butter to a boil. Remove from heat, cover, and rest at room temperature.

Strain the water from the potatoes and return to the stove on low heat, shaking a bit until just dry.

Remove and pass the potatoes through a food mill or ricer into another pot, and strain the cream and butter into the potatoes. Stir well over medium heat to combine. Season to taste with salt and pepper.

To assemble and serve

Preheat oven to 400°F.

Using a slotted spoon, transfer the meat and vegetables into the roasting pan or casserole dish and spread to make an even layer.

Spoon the mashed potatoes on top and spread to cover. Fluff the top of the potatoes a bit with a fork to make several peaks. Evenly sprinkle the grated Gruyère on top and bake for 20 minutes, or until the top is golden brown and nicely crusted.

After baking, drizzle on a touch of crème fraîche if desired.