Season roast with 3 tablespoons kosher salt, wrap in plastic, and refrigerate (3 hours to 3 days).
STEP 2
Preheat oven to 275 degrees F.
STEP 3
Heat 2 tablespoons oil in a large pot over high heat; brown the meat on all sides (10 to 12 minutes). Transfer to a plate.
STEP 4
Reduce heat to medium-high; add remaining oil to the pot. Cook onions and remaining salt until browned (6 to 8 minutes). Add garlic and tomato paste, cooking until fragrant (1 minute).
STEP 5
Add wine and bay leaves; reduce for 4 minutes. Stir in flour, then broth and pepper; bring to a boil.
STEP 6
Place meat and juices back in pot. Surround with carrots, celery, and potatoes. Cover and bake until tender (3 to 3.5 hours). Rest covered for 45 minutes.
STEP 7
Slice meat against the grain. Serve with vegetables and spoon sauce over top; garnish with parsley and chives.