Step 1: Gather your ingredients. Start by thinly slicing your orange. The thinner the slices, the more surface area for the essential oils to release their fragrance.
Step 2: Add all solid ingredients to a medium-sized saucepan or a small slow cooker. Place the orange slices, fresh cranberries, cinnamon sticks, whole cloves, ground nutmeg (or whole pieces), fresh rosemary sprigs, and star anise pods (if using) into the pot.
Step 3: Fill the pot with water. Pour in 6-8 cups of water, or enough to comfortably cover all the ingredients. You want the pot to be full enough to simmer for a few hours without drying out too quickly, but not so full that it boils over.
Step 4: Bring to a gentle simmer. Place the pot on your stovetop over medium-high heat and bring the water to a boil. Once boiling, reduce the heat to low, ensuring the mixture maintains a gentle, consistent simmer.
Step 5: Allow to simmer, replenishing water as needed. Let your Christmas simmer pot do its magic for 2-4 hours, or even longer. As the water evaporates, the fragrance will start to lessen. Simply add more water to keep the pot full and the aroma going strong.
Step 6: (Optional) Add vanilla extract. If you desire a slightly sweeter, creamier scent, stir in 1 teaspoon of vanilla extract during the last hour of simmering.
Step 7: Enjoy the aroma! Your home will soon be filled with the most incredible, natural Christmas scent. Turn off the heat when you’re done, or allow it to cool and store in an airtight container in the fridge for up to two days. Reheat gently on the stovetop, adding more water if necessary.