Line a sheet pan with parchment paper or plastic wrap. Place watermelon chunks on the pan, leaving space between the pieces and cover with plastic wrap and freeze for 1 hour or until
- If preparing the watermelon in advance for smoothies later in the week, transfer to a plastic storage bag and freeze until ready to use.
- Place frozen watermelon chunks in a blender and top with milk, yogurt and chia seeds. Add honey and a squeeze of fresh citrus, if desired.
- Blend until smooth.
Serve watermelon smoothies immediately, using chilled glasses. Garnish with a wedge of watermelon and fresh mint, if desired.