Season chuck with 1 1/2 teaspoons salt; blot dry with paper towels.
Heat oil in a large skillet over medium-high heat. Brown beef in 3 batches, about 5 minutes each, leaving gaps between cubes.
Cook onion in same skillet 5 minutes. Stir in garlic, ancho powder, and cumin 30 seconds.
Transfer everything to a 6-quart crockpot. Add tomatoes, beans, broth, and remaining salt. Cover; cook on low 7 to 8 hours until beef is fork-tender and at least 145°F.
Whisk masa harina and warm water; stir into chili. Cook uncovered on high 30 minutes until broth coats beef.