Place the semisweet chocolate in a double boiler over barely simmering water and melt while stirring. Place the white chocolate in a separate double boiler over barely simmering water and melt while stirring. Once the chocolates are melted and smooth, remove from the heat. Line a sheet pan with parchment or waxed paper. Grasp the stem or green leaves of the strawberry and dip into the semisweet chocolate, twisting as it is lifted out. Let the excess chocolate drip off and then place on the parchment paper. Repeat with the rest of the strawberries. Dip a fork in the white chocolate. Hold the fork over the chocolate covered strawberries and quickly shake it back and forth to create lines of white chocolate on the semisweet chocolate. Set the strawberries aside to allow the chocolate to harden, about 30 minutes.