Start by patting the beef chuck cubes dry with paper towels, then season them generously with salt and pepper. Heat a large heavy pot or Dutch oven over medium-high heat, adding a splash of olive oil. Sear the beef cubes in batches for about 5-7 minutes until they develop a rich, brown crust, then set aside.

In the same pot, add a little more olive oil if necessary and toss in the chopped onions. Sauté over medium heat for about 5-7 minutes, stirring frequently until they become translucent and lightly golden.

Next, stir in the chopped red and yellow bell peppers along with the minced garlic. Cook for another 5-7 minutes until the peppers have softened and the garlic is fragrant.

Sprinkle in the sweet and smoked paprika, caraway seeds, marjoram, and optional cayenne pepper. Stir for about a minute until the spices are toasted and fragrant.

Add the tomato paste to the pot, stirring thoroughly to coat the vegetables and spices. Cook for an additional minute to caramelize it slightly.

Pour in the beef broth and red wine, using a wooden spoon to scrape up any brown bits stuck at the bottom of the pot. Bring the mixture to a gentle simmer.

Carefully place the browned beef back into the pot along with the bay leaf. Stir everything together and allow to simmer before reducing the heat to low. Cover and cook for 2-3 hours.

After the beef has become tender, create a slurry by mixing flour with a little water in a separate bowl. Stir this mixture into the goulash and cook for an additional 5-10 minutes uncovered until the stew thickens.

Remove the pot from heat, then stir in the red wine vinegar. Adjust seasoning with salt and pepper as necessary.

Ladle the steaming German Goulash into bowls, garnishing with freshly chopped parsley. Serve hot alongside spätzle, mashed potatoes, or crusty bread.