Add the bacon drippings or olive oil to a large skillet. Preheat over medium heat until the drippings or oil is just hot. Add the diced onion and diced green sweet pepper. Cook the onion and pepper until they're tender.
Add the unpeeled, sliced russet potatoes, the sliced sweet potatoes and water to the vegetables in the skillet. Sprinkle the mixture with the seasoning or seasoned salt.
Cover and cook over medium heat for 12 to 15 minutes or until potatoes are tender, turning potatoes once or twice.