1. Preheat oven at 375°F.
2. In a 12-inch sauté pan or casserole heat the olive oil over medium-high heat. Render the pancetta until crispy. Add the shallots, potatoes and the garlic; lightly color them without burning the garlic. Season with salt and pepper.
3. When the potatoes are colored add the herbs and white wine, cover the pan, turn down the heat to a low flame and cook them slowly for about 10 minutes. Add the tomatoes and cover them again. Cook for approximately 20-25 minutes; the potatoes should be tender but not mushy. When tender remove the cover, add the Plugrá butter and reduce the liquid to a syrup like consistency.
4. Reserve the potatoes in the pan away from the heat until your main entree is ready.