This ice cream will keep its flavor for a while if you pack it firmly in a small metal bowl, cover it tightly first with plastic wrap and then with foil, and put it in the freezer. It’s so delicious, though, I doubt you’ll have any left over.
In a large bowl, combine the lemon zest, lemon juice, and sugar and stir to combine well.
Gradually add the cream, salt, and, if desired, the food coloring, stirring constantly. Continue to stir until sugar is dissolved.
Pour the mixture into ice cube trays with the dividers removed or into an 8 x 8 inch METAL baking pan. Cover tightly with foil and freeze until the mixture is solid around the edges and mushy in the middle. Stir well with a wooden spoon, cover with foil, and continue to freeze until completely firm. Serves 2.