Cook turkey in a large nonstick skillet over medium-high heat until browned, stirring to crumble. Drain in a colander.
Heat oil in skillet over medium heat. Add onion and garlic, and sauté 7 minutes. Add chili powder, oregano, cumin, salt, and red pepper; cook 1 minute. Return turkey to skillet; stir in 2 1/4 cups water, prunes, and beans. Bring to a boil; reduce heat, and simmer, uncovered, 5 minutes. Serve Turkey-and-Black Bean Chili over rice, if desired.