1. Preheat oven to 325°F
2. Bring cream and milk just to simmer in heavy medium saucepan over medium heat; remove from heat
3. Add chocolate; whisk until melted and smooth
4. Whisk yolks and sugar in large bowl to blend; gradually whisk in hot chocolate mixture
5. Strain mixture into another bowl; cool 10 minutes, skimming any foam from surface
6. Divide mixture among six 3/4 cup custard cups or soufflé dishes; cover each with a lid or foil
7. Place cups in large baking pan; add enough hot water to pan to come halfway up sides of cups
8. Bake until custards are set but centers still move slightly when gently shaken, about 55 minutes
9. Remove from water, remove lids or foil and chill custards until cold, about 3 hours

Instructions for the Thermomix:

1. Preheat oven to 325°F
2. Scale cream and milk into TM bowl; heat for 5 minutes at 90°C speed 2
3. Scale chocolate into TM bowl: heat for 5 minutes at 60°C speed 2
4. Scale sugar into TM bowl; heat for 6 minutes at 50°C speed 3-4
5. Add yolks one at a time through the hole in the lid after the first 2 minutes, until all 6 are added (within the first 5 minutes); continue to stir and heat for the remaining minute
6. Strain mixture into another bowl; cool 10 minutes, skimming any foam from surface
7. Divide mixture among six 3/4 cup custard cups or soufflé dishes; cover each with a lid (or foil) for a moist top without any visibly developed surface tension
8. Place cups in large baking pan; add enough hot water to pan to come halfway up sides of cups
9. Bake until custards are set but centers still move slightly when gently shaken, about 40 to 45 minutes
10. Remove from water, remove lids and chill custards until cold, about 3 hours