Start by lining a 9×13-inch baking dish or a baking sheet with parchment paper or a silicone mat.

In a heavy-bottomed saucepan, combine the unsalted butter, granulated sugar, salt, and water over medium heat, stirring constantly.

Once your toffee mixture reaches the hard crack stage, remove it from the heat and pour it onto the prepared baking sheet.

While the toffee is still warm, sprinkle 1 cup of chocolate chips evenly across the top, let them sit for about 2 minutes, then spread the melted chocolate.

Sprinkle ½ cup of your chopped nuts over the surface and gently press them into the chocolate.

Let the toffee sit at room temperature for about 2 hours to cool completely.