Preheat the oven to 350°F (180°C), conventional heat. In a bowl, mix together the mustard, honey, and 1 tablespoon olive oil. Peel and thinly slice the onions. Crush the garlic. Peel the potatoes, cut them into large wedges, rinse, and dry them.

Spread the onions on the bottom of a baking dish and place the pork roast on top. Season with salt and pepper, then generously brush the pork with the honey-mustard mixture. Add the garlic, thyme, and bay leaves. Pour the broth and white wine (if using) around the meat. Bake for 1 hour 15 minutes, basting every 20 minutes. Add water as needed. Add the potatoes around the meat and lightly salt them. Continue baking for 45 minutes to 1 hour, turning the potatoes halfway through.

Before adding the cream: In the last 20–25 minutes of cooking, the meat will be very tender, and the juices hot and reduced. The cream will thicken the sauce without boiling too long.

Troubleshooting tips: Use full-fat or light thick sour cream or crème fraîche—both work well. If the sauce is too thin, remove the meat and increase the oven to 375°F (190°C) for the last 10 minutes. If the sauce is too thick, add a little hot broth.

Result: The sauce is creamy and slightly sweet and savory. The potatoes are well coated, and the pork is super tender. Slice the pork and serve with the sauce and potatoes.