Combine Purée Ingredients: In a medium saucepan, combine the chopped pears, cranberries, water, maple syrup, cinnamon stick, and orange zest.

Simmer Gently: Bring the mixture to a gentle simmer over a medium heat. Once simmering, reduce the heat to low, cover the pan, and let it cook for 15-20 minutes. You're looking for the pears to become very soft and the cranberries to burst.

Cool and Blend: Remove the pan from the heat and take out the cinnamon stick. Allow the mixture to cool for about 10 minutes. What works best for me is transferring the warm mixture to a blender or using an immersion blender directly in the pan. Blend until it's completely smooth.

Sieve for Smoothness (Optional but Recommended): For an extra-smooth, professional-feeling purée, pass the mixture through a fine-mesh sieve into a bowl or jug, using the back of a spoon to press it through. This step removes any tough skins from the cranberries. I never skip this part; it makes a huge difference to the final texture.

Chill Thoroughly: Cover the purée and place it in the refrigerator to chill completely for at least 2 hours, or ideally overnight. This is the perfect make-ahead step for a stress-free Christmas morning.

Assemble the Bellinis: When you're ready to serve, spoon about 2-3 tablespoons (or 30-40ml) of the chilled purée into the bottom of a champagne flute.

Top with Prosecco: Slowly top up the glass with chilled Prosecco. The purée will cause it to fizz up quite a bit, so pour gently. Give it a very gentle stir with a long spoon to combine.

Garnish and Serve: Garnish each glass with a few fresh cranberries and a small sprig of rosemary. Serve immediately while it's cold and sparkling.