Heat olive oil in a large Dutch oven over medium heat. Add all the chopped onions and cook for a full 15 minutes, stirring occasionally, until they are very soft, translucent, and beginning to turn golden. Don't rush this step—the onions will reduce significantly and develop natural sweetness that forms the flavor foundation.

Stir in the chopped green bell pepper, diced tomato, and minced garlic. Cook for another 5 minutes until the vegetables soften and become fragrant.

Remove the onion mixture from the pot and transfer to a bowl, setting aside. Add the beef cubes to the same pot (add a splash of oil if needed). Working in batches if necessary to avoid crowding, cook over medium-high heat for 5 to 10 minutes, turning occasionally to brown all sides. You want a deep, caramelized crust on the meat.

Return the onion mixture to the pot with the browned beef. Add the salt, black pepper, sweet Hungarian paprika, dried marjoram, caraway seeds, and tomato paste. Stir thoroughly to coat the meat and vegetables evenly. Cook for 1 minute, stirring constantly, to toast the spices.

Pour in the beef broth and red wine, stirring and scraping the bottom of the pot with a wooden spoon to release all the browned bits. Add the bay leaf. Bring to a full boil over medium-high heat.

Once boiling, reduce heat to low so the liquid maintains a gentle simmer. Cover the pot with the lid positioned slightly askew to allow a little steam to escape. Simmer for 1.5 to 2 hours, stirring occasionally, until the beef is fork-tender and the sauce has reduced into a thick, rich gravy.

Remove and discard the bay leaf. Taste and adjust seasoning with additional salt and pepper if needed. Garnish generously with fresh chopped parsley. Serve hot over spaetzle, buttered egg noodles, or boiled potatoes.