Heat the olive oil in a large pot over medium heat. Add the ground beef and cook until browned, breaking it up with a spoon as it cooks.
Stir in the onion and garlic. Cook for 2 minutes until the onion starts to soften.
Add the smoked paprika, fennel seeds, and red pepper flakes. Stir for 30 seconds to toast the spices with the beef.
Add the shredded cabbage, diced tomatoes with their juice, beef broth, salt, and black pepper. Stir to combine.
Bring the mixture to a simmer, then reduce the heat to medium-low. Cook uncovered for 15 minutes, stirring occasionally, until the cabbage is tender but still has some bite.
Taste and adjust salt if needed before serving.