Lemon Mousse

• 2 Tbsp. water
• 1 tsp. gelatin
• 4 oz. (0.5 cup) unsalted butter
• 4 oz. (0.75 cup) sugar
• 3 Tbsp. finely grated lemon zest
• 0.5 cup fresh lemon juice
• 1 pinch of salt
• 6 large egg yolks, room temperature
• 0.75 cup heavy whipping cream

Wash off the lemons, dry them, and zest them before you juice them. Pick out any pips that get into your juice.

Fill the bottom half of a double boiler with water, but not so full that the top half touches the water. Place the top half in the bottom half and melt the butter in this over low heat. Turn off the heat and whisk in the sugar, salt, lemon zest, and juice.

Now whisk in the egg yolks until the mixture is smooth, and then turn the heat back on very low. Cook, stirring constantly and never allowing the water to boil, until the mixture thickens. Watch as you stir; as you first start stirring, when you lift your spoon out, you can watch the mixture keep swirling in the direction you were stirring. As the mixture cooks, this tendency to continue in the same direction as you were stirring lessens until, when you stop stirring, the mixture stops and backs up in the opposite direction. This means the mousse is cooked and you are done. Try it once or twice and you'll know what I mean. It'll take 10–20 minutes depending on the ambient temperature and how good you are at not boiling the water under the pan.

Now put the teaspoonful of gelatin and 2 Tbsp. of cold water in a small pan, put the pan directly on low heat, and take it off again almost immediately. Touch the bottom of the pan with your hand to make sure it's not too hot. Put the pan back on the heat briefly, then pick it up and swirl it around, and keep repeating the process until the gelatin dissolves, which may only take a matter of a few seconds.

With everything off the heat, whisk the dissolved gelatin into the cooked mousse. There are some who would have you strain the mixture at this point, however, if you used a microplane grater to grate your lemon zest, and if you have been diligent in your stirring, you should have no lumps; the only solids should be the fine lemon zest, which adds a nice bit of texture to your final mousse. Strain it if you wish and have fun cleaning the seive. Pour it all into a bowl and let it cool, stirring occasionally.

In another bowl, large enough that you won't get cream splattered everywhere, whisk the cream into stiff peaks (but don't overdo it) then gently fold the cream into the mousse in small batches.

Divide the mousse into four glasses or other containers, cover them with wax paper or plastic wrap, and set them in the fridge to chill for at least two hours, or overnight if you can.

Thanks to our man in Durness for the tip on how to tell your mousse is cooked and the much improved method for dissolving the gelatin.