01 - Heat olive oil in a large Dutch oven or heavy-bottomed pot over medium-high heat. Add beef cubes and brown on all sides, about 5 minutes. Remove beef and set aside.
02 - In the same pot, add onion and cook until translucent, about 4 minutes. Add garlic, red bell pepper, and green bell pepper; sauté for an additional 3 minutes.
03 - Stir in tomato paste and cook for 1 minute. Return beef to the pot.
04 - Add crushed tomatoes, kidney beans, black beans, ground cumin, smoked paprika, chili powder, cayenne pepper if using, oregano, salt, black pepper, beef broth, and brown sugar. Stir until combined.
05 - Bring chili to a simmer. Cover and cook over low heat for 1 hour, stirring occasionally.
06 - While chili simmers, whisk together flour, cornmeal, baking powder, baking soda, salt, and sugar in a bowl. In another bowl, whisk egg, buttermilk, and melted butter. Combine wet ingredients with dry and stir just until incorporated; avoid overmixing.
07 - After 1 hour of simmering, uncover chili and bring to a gentle simmer. Drop tablespoon-sized dollops of cornbread batter onto the surface of the chili, making approximately 12 dumplings.
08 - Cover the pot and cook over low heat for 20 minutes, until dumplings are puffed and cooked through.
09 - Serve hot, optionally garnished with fresh cilantro, sliced jalapeños, or shredded cheese as desired.