In a small bowl, dissolve the cornstarch in the water and set aside. Melt
butter in a medium skillet over medium heat and add shallots
. Saute until translucent, about 5 minutes. Carefully add cognac
and simmer until alcohol
vaporizes, about 1 minute. Add shrimp base, heavy cream
and salt and pepper, to taste. Simmer
while stirring for 3 minutes. Add cornstarch
mixture and simmer, while stirring, until thickened. Set aside and keep warm.