Cut the lemons into halves.

Using a spoon or melon baller, scoop out the inside of the lemons, being very careful to not pierce through the bottom.

Place them in a strainer. Using a spoon, squeeze out the lemon juice (approximately ⅔ cup juice). Set aside.

Place double cream, sugar and lemon zest in a small saucepan over medium heat. Bring to a simmer. Stir constantly and do not boil the mixture. Simmer for about 3 minutes. Remove from heat.

Add lemon juice. Whisk vigorously until combined.

Let cool 10 minutes.

Stir mixture again and divide among 6 lemon halves. You can also use small dessert glasses.

Cover each lemon with plastic (cling) wrap. Refrigerate until set, 3 hours or overnight.

Garnish with lemon zest and mint leaves if you like.