Process the olives and garlic into a paste using a hand blender.
In a bowl, mix the minced pork, capers, thyme, finely chopped parsley, egg yolk, flour, and brandy. Season with salt and pepper.
Brush each roulade generously with the olive paste. Spread the seasoned pork mixture evenly on top, roll up tightly, and tie with kitchen twine. Season the outside with salt and pepper. Refrigerate until ready to cook.
Heat fat in a saucepan over medium-high heat. Sear the roulades on all sides until browned, about 3-4 minutes per side. Remove and set aside. Add the finely chopped onions and fry over medium-high heat, stirring occasionally, until dark brown, about 8-10 minutes. Return the roulades to the pan. Deglaze with broth, scraping up any browned bits. Bring to a boil and simmer vigorously for 10 minutes. Add the red wine and simmer vigorously for another 10 minutes. Stir in the tomato paste. Cover and cook over low heat for at least 1 hour, until the pork filling reaches 63°C / 145°F internally. Cook longer if needed.
Remove the roulades from the pan and keep warm on a plate tented with foil.
Increase heat to medium-high and simmer the sauce uncovered for another 10 minutes to reduce. Return the roulades to the pan and simmer together for about 10 minutes before serving.