1. Cut beef chuck roast into uniform 1.5-2 inch cubes. Pat completely dry with paper towels.

2. Season beef generously with salt and pepper on all sides. Let sit 15 minutes at room temperature.

3. Heat large Dutch oven or heavy skillet over medium-high heat for 2-3 minutes until hot.

4. Add neutral oil and swirl to coat. Working in batches, add beef in single layer with space between pieces.

5. Let beef sear undisturbed for 3-4 minutes until deep brown crust forms on bottom.

6. Using tongs, flip each cube and sear another 2-3 minutes. Continue until all sides caramelize (8-10 minutes per batch).

7. Transfer seared beef to a plate. Repeat with remaining batches.

8. To same pot, add diced onions over medium heat. Cook 5-6 minutes, scraping up browned bits with spoon.

9. Add minced garlic and cook 1 minute until fragrant. Add chili powder, cumin, smoked paprika, oregano, and cayenne.

10. Cook spices 2-3 minutes, stirring constantly until fragrant and raw spice taste disappears.

11. Stir in tomato paste and cook 1 additional minute to incorporate fully.

12. Return seared beef and accumulated juices to pot with spiced aromatics.

13. Add crushed tomatoes, kidney beans, black beans, beef broth, brown sugar (if using), salt, and pepper.

14. Stir thoroughly ensuring all ingredients combine evenly. Transfer to large slow cooker.

15. Cook on low for 6-8 hours until beef is fall-apart tender and flavors are melded beautifully.

16. Alternatively, cook on high for 3-4 hours for accelerated cooking.

17. Approximately 30 minutes before serving, taste and adjust seasonings.

18. If chili is too thin, leave lid off for final 30 minutes to allow evaporation and thickening.

19. If too thick, add beef broth or water incrementally until desired consistency achieved.

20. Ladle into serving bowls and top with desired garnishes.

21. Serve while hot with cornbread or crusty bread.