Wash the tomatoes thoroughly and peel them.
Cut the tomatoes into appropriate sizes.
Put the tomatoes, lemon juice, and sugar into a blender and blend until smooth.
Pour the blended tomato mixture into an airtight container and place in the freezer.
Scrape with a fork every 30 minutes and freeze for 3 to 4 hours.
Scoop the tomato sorbet into a bowl and serve.