Cut thinly shallot, fry in butter. Add chopped carrot, salt, pepper, nutmeg and 1 tbsp of water. Cover with a lid and stew for 15-20 minutes until carrot softens. Mash the vegetables through a sieve, adding step by step hot cream.
Whisk eggs and 1 yolk, mix with carrot puree. Put carrot mass in greased molds, filling them at 2/3 of volume. Put the molds on water bath and in oven, bake over 390°F for 30 minutes. Take the molds out of the oven, leave for 2 minutes, then remove the flans on plates and pour the sauce.
To prepare sauce, whisk the remaining egg yolks with stock, and cook on water bath stirring until mass thickens. Then add salt, pepper, vermouth, lemon juice and zest. Add chopped basil in prepared sauce.