Meanwhile, break open the
garlic heads and peel the
cloves. Put them in a saucepan and cover with cold water. Bring to boil for a few minutes. Repeat this process 5 times, drain the
garlic and put it, while still
warm, in the
blender. Add the
tarragon and make a fine puree. Pass the
lamb reduction through a sieve into a saucepan, add the
cream and continue
cooking for 2 minutes. Then bind it with the
garlic puree and whisk in 1 1/2 oz of
butter. Put the
sauce again through a sieve and rectify the seasoning.