Step 1In a small saucepan, bring the half-and-half to a simmer over medium heat. Remove from heat. Place the chocolate in a heatproof bowl and stir in 6 tablespoons (90 ml) of the hot half-and-half until the chocolate melts. Add the remaining half-and-half as needed to achieve a good sauce consistency. Stir in vanilla and salt.
Step 2Use immediately or cover and set aside for up to a few hours. If the sauce becomes too thick, place the bowl in a pan of simmering water and stir 1 or more tablespoons of hot water into the sauce to reconstitute. The sauce can be made a day ahead, covered and refrigerated.