Heat heavy cream in a medium saucepan over low heat. Add monk fruit sweetener, arrowroot powder, salt and lemon zest, whisking well.

Whisk in the egg yolks. Increase heat to medium low. Continue whisking until the mixture begins to simmer.

Remove from heat. Add vanilla extract and lemon juice, mixing well.

Pour the custard into four 4-ounce ramekins and set aside.

For the meringue, whip egg whites and cream of tartar with an electric mixer until soft peaks form.

Add monk fruit sweetener and vanilla extract. Whip on high until stiff peaks form.

Spoon the meringue on top of the custard.

Turn broiler on high and place the top rack about 8-inches from the broiler.

Place ramekins under the broiler until the meringue is lightly browned (about 1 to 2 minutes, being careful not to burn the meringue).

Transfer ramekins to the refrigerator and chill for 2 hours before serving.