Place the watermelon chunks in a blender and blend until smooth and uniform, about 30 seconds, producing a bright pink puree.
4 cups seedless watermelon chunks
Add lemon juice to the watermelon puree and blend briefly to combine, about 10 seconds. Pour the mixture into a freezer-safe container.
1 tablespoon lemon juice
Cover the container with a lid or plastic wrap and place in the freezer. Every 30 minutes, remove the container and stir vigorously with a silicone spatula to break up ice crystals, ensuring a smooth texture.
Repeat the stirring process 4-5 times over 2-3 hours, until the sorbet is firm yet scoopable, with a consistent texture and no large ice crystals visible.
Once frozen to the desired consistency, serve the sorbet scooped into bowls, garnished if desired. The final product should be smooth, icy, and vibrant pink in appearance.