Heat the oil in a large heavy-bottomed pot or Dutch oven over medium-high heat. Pat the beef cubes dry and sear them in batches until browned on all sides. Remove beef and set aside.

Lower the heat to medium. Add the finely diced onions to the pot. Sauté slowly for 15-20 minutes, stirring occasionally, until the onions are very soft and golden brown. This step is crucial for the sauce's texture.

Stir in the minced garlic and tomato paste, cooking for 1 minute until fragrant. Add the smoked paprika, hot paprika, and marjoram, stirring constantly to prevent burning.

Pour in the red wine to deglaze the pot, scraping up any browned bits from the bottom with a wooden spoon. Let the wine simmer for 3-4 minutes to reduce slightly.

Return the browned beef and any accumulated juices to the pot. Pour in the beef broth and add the bay leaf. The liquid should just barely cover the meat.

Bring the mixture to a boil, then reduce the heat to low. Cover and simmer gently for 1.5 to 2 hours, or until the beef is fork-tender.

Remove the lid for the last 20 minutes of cooking to allow the sauce to thicken further. Season generously with salt and pepper to taste.

Remove the bay leaf and serve hot over polenta, mashed potatoes, or gnocchi.