Step 1

Season the brisket on all sides with salt and pepper.

Step 2

In a large oven-safe braiser, heat the oil over medium-high heat. Add the brisket and cook, turning occasionally, until browned, about 10 minutes. Reduce the heat to medium. Add the leeks, carrots, and celery. Season with salt. Cook, stirring often, until softened, about 10 minutes. Add the garlic and stir until fragrant, about 1 minute. Add the tomato paste and stir to toast, 1 minute. Add the wine to deglaze and use a wooden spoon to scrape any brown bits from the bottom of the pan. Bring the wine to a boil and cook for 3 to 5 minutes. Add 2 1/2 cups of stock, the tomatoes and rosemary. Bring back to a boil, then reduce the heat to medium-low. Simmer, covered, stirring occasionally, until the beef is tender, about 2 hours.

Step 3

Place an oven rack in the middle position. Preheat the oven to 400 degrees F.

Step 4

Remove the lid from the brisket and continue to cook until the sauce is reduced and thickened to a stew-like gravy, 20 to 30 minutes. Turn off the heat. Using two forks, break up the meat into smaller chunks, but not shredded. Add the peas and stir to combine. Arrange the potato smiles on top in concentric circles.

Step 5

Bake until golden, steamy and bubbling, 45 to 50 minutes. Let cool slightly. Garnish with the parsley and chives. Serve with ketchup, if desired.