Heat olive oil in a large pot over medium-high heat.
Add beef chunks and sear until browned on all sides. Remove and set aside.
Add onion and garlic to the pot; sauté 3–4 minutes until softened.
Stir in tomato paste, smoked paprika, chili powder, cumin, and red pepper flakes. Cook 1 minute.
Return beef to the pot and add fire-roasted tomatoes and beef broth.
Season with salt and pepper, then bring to a low simmer.
Cover and cook 60–90 minutes until beef is tender.
Optional: Add bell pepper, jalapeño, or zucchini during the final 20 minutes.
Taste and adjust seasoning before serving.