Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.

In a large bowl, cream together the softened butter, white sugar, and brown sugar until smooth and creamy.

Beat in the eggs one at a time, ensuring each is fully mixed in. Stir in the vanilla extract.

In a small bowl, dissolve the baking soda into the hot water. Pour this mixture into the batter along with the salt, and stir to combine.

Gradually add the all-purpose flour, mixing until just incorporated. Do not overmix.

Fold in the semisweet chocolate chips and chopped walnuts.

Drop the dough by large spoonfuls onto the prepared baking pans, spacing them about 2 inches apart.

Bake for 10 minutes in the preheated oven, or until the edges are lightly browned and the centers are still soft.

Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.