1. Lightly spray an 8-inch by 5-inch loaf pan with nonstick spray and line with parchment paper. Leave an overhang on the long sides to make it easy to remove the halvah from the pan.

2. Mix the tahini, toasted sesame seeds and the salt in a medium bowl until well combined and set aside.

3. Place the sugar and 1/2 cup of water in a small saucepan and cook over low heat, stirring with a silicone spatula, until the sugar dissolves, about 4 minutes. Clip on a candy thermometer and increase the heat to medium high. Cook the syrup and brush the sides of the pan with a wet pastry brush, as needed, to prevent sugar crystals from forming on the sides of the saucepan. Continue doing this until the thermometer registers 250F which will take about 7 to 10 minutes. Immediately remove from the heat.

4. Gradually drizzle the syrup into the reserved tahini mixture and continue to mix just until the halvah comes together and starts to pull away from the sides of the bowl. This should take less than a minute. Be careful not to over mix or the halvah will become too crumbly. Pour into the prepared pan and allow to cool completely and set.

5. Melt the chocolate in a heatproof bowl over simmering water being careful not to allow the bowl to touch the water. Stir often until the chocolate is completely melted. Remove from the heat. Line a baking sheet with foil or parchment and place a wire cooling rack on top. Invert the halvah onto the wire rack and peel off the parchment that lined the loaf pan. Pour the chocolate over the halvah and spread to cover the entire top and sides. Sprinkle with the sea salt and sesame seeds. Let the chocolate set for about 30 minutes before slicing and serving.