Crust

1. Using a stand or hand mixer, mix the butter, salt and egg yolks.
2. Add flour and mix just until clumps form.
3. Roll dough into a ball, wrap in plastic and refrigerate for at least an hour.
4. Using a biscuit cutter or large-mouthed cup, cut out four circles of dough an inch larger in diameter than the tartlet cups.
5. Press dough rounds into cups, repairing any cracks or filling spaces with unused dough.

Custard

1. Simmer the water and sodium citrate together and stir until dissolved.
2. Add cheese and let melt.
3. Remove from heat and stir in cream (mixture will look like it has seized).
4. Add egg and blend with an immersion blender.

Tempered Chocolate*

1. Melt half of the chocolate in a glass or copper bowl over a pot with simmering water (making sure the water does not touch the bowl, raising the temperature of the chocolate to 115 F.
2. Once 115 F is achieved, remove bowl of chocolate and, using one small piece at a time, stir the remaining chocolate in until the mixture falls to 90 F.
3. The chocolate is now in temper. Keep chocolate at between 89 F and 91 F by returning it to steam for a few moments if it gets too cool.

Assembly

1. Divide custard batter between the four dough-lined tartlet cups and set cups on a sheet pan.
2. Bake at 350 for 18-20 minutes or until custard does not wobble when the sheet pan is given a quick shake.
3. Remove from oven and let cool on a cooling rack, then store in refrigerator until chilled.
4. Pour thin layer of tempered chocolate onto top of custard and spread evenly.
5. Return to refrigerator until ready to serve. Will keep for up to 3 days.