Heat 1/3 cup oil in a Dutch oven (or another thick-walled iron cooking pot with a tight-fitting lid) over medium-high heat. Place pork in a large zip-top bag. Combine 1/2 teaspoon of the salt, plus pepper, cumin and cinnamon; sprinkle over pork. Add flour to pork mixture; seal bag. Shake to coat. Add pork mixture to pan; sauté 4 minutes, turning to brown on all sides. Remove pork from pan. Heat remaining oil over medium-high heat. Add remaining 1/2 teaspoon salt, potato and onion to pan; sauté 3 minutes. Add garlic; sauté 1 minute, stirring often. Return pork to pan. Stir in broth; bring to a boil. Reduce heat and simmer 25 minutes or until pork is done and vegetables are tender.
Sprinkle 1 tablespoon green onions over each serving, if desired.