Preheat oven to 375°F.
In a medium bowl, using an electric mixer, beat butter, sugars, salt, vanilla until well combines, but not until fluffy. Add egg. Beat for a couple of more seconds.
In a medium bowl, combine baking soda and hot water and stir. Make sure that there are no big crumbles left over. Let sit for a minute or two.
Add flour to baking soda mixture. Combine dry ingredients and wet ingredients and mix on low speed, just until absorbed.
When cutting chocolate do not use knife, since you’ll lose a lot of extra chocolate, instead break with your hands. Should be about 1 cm big.
In small bowl, combine ¾ of the chocolate chunks to nuts, either use walnuts or pecans, and put aside the extra chunks. (For better taste, roast nuts on baking sheet at 375°F for 5 minutes. Stir chocolate mixture into dough.)Refrigerate for a half an hour.
Shape the dough into 1 ½ inch balls, use a 1 ½ ice cream scoop so the dough pieces are all the same size, and drop them about 3 inches apart onto an ungreased baking sheet. Add the remaining chocolate chunks on top of dough balls, about 3-4 chunks on each ball. Bake 9-12 minutes or until golden. Let sit for 5 minutes, then transfer to wire rack.