Preheat your oven to 325°F (160°C). Season the short ribs generously with salt and black pepper. In a Dutch oven, heat a drizzle of oil over medium-high heat. Sear the short ribs on all sides until browned, about 3-4 minutes per side. Remove and set aside.

In the same Dutch oven, add the diced leeks and halved California prunes, stirring to incorporate. Sauté for about 4-5 minutes until prunes start to caramelize.

Pour in the red wine and vinegar to deglaze the pan, scraping up the brown bits. Allow to simmer for 2-3 minutes, then add olives, capers, caper brine, garlic, bay leaves, oregano, and brown sugar. Mix and bubble for another minute.

Return the short ribs bone-side down within the mixture. Cover and transfer to the oven. Braise for 2 to 2.5 hours until tender.

Carefully remove the short ribs and set aside. Strain the liquid through a sieve back to the Dutch oven. Over low heat, whisk in butter until emulsified for a glossy finish.

Add remaining prunes, olives, leeks, and capers to the sauce. Taste and adjust seasoning if needed. Heat through before serving.

Drizzle the sauce over the short ribs on your serving dish. Enjoy your Short Rib Marbella with mashed potatoes or crusty bread.