How to Make It
Heat a large cast-iron skillet over high. Cut 2 (1/2-inch-thick) round slices from onion. Chop remaining onion; reserve. Add onion slices and jalapeño to pan; cook 8 minutes, turning to char on all sides. Remove onion slices; chop. Remove jalapeño; thinly slice.
Combine stock and tortillas in a food processor; process until combined.
Heat oil in a large Dutch oven over medium-high. Add beef; cook 6 minutes, stirring to crumble. Add reserved chopped fresh onion and garlic; cook 5 minutes. Stir in chili powder, cumin, and paprika. Stir in stock mixture, tomatoes, salt, and beans; bring to a simmer. Cook 10 minutes. Place 1 3/4 cups chili in each of 4 bowls. Top each serving with 1 tablespoon yogurt, 2 tablespoons cheese, charred chopped onion, and jalapeño.