This paper presents an optimal procedure for controlled electricity black start for electricity distribution grids in reaction to adverse events or malicious cyber attacks resulting in the interruption of the main power supply from transmission network. The islanded operation is supposed to be guaranteed by an electric energy storage system, which covers the network imbalance between demand and supply from distributed generation during the sequential reconnection of medium voltage branches. The objective is to restore the service to the consumers while avoiding violation of technical constraints in terms of storage power flow and battery capacity. The discussion of simulation results assesses the effectiveness of the proposed approach in the context of a simplified network model and gives rise to relevant remarks and requirements for further developments.