For the beef stew, bring meat to room temperature, about 30 minutes.
Preheat a large Dutch oven over medium-high heat and oven to 300˚F with racks in lower third and upper third of oven.
Pat meat dry and season with salt and pepper. Add about 1 tablespoon oil to the pan, 1 turn of the pan, melt about a tablespoon of butter into oil, and when it foams, add about ⅓ of the meat. Brown evenly on all sides and remove, then repeat with more oil and butter as needed, removing meat to platter or tray as you work. Add remaining oil and butter, and when butter foams, add the onions, fennel, garlic, bay, citrus and rosemary, then partially cover and soften about 10 minutes. Add tomato paste, stir, add wine and reduce 2-3 minutes. Add the beef, stock, semi-dried or sundried tomatoes, olives and chili flakes or paste. Cover and place in oven for about 2 hours until very tender.