Let the butter come to room temperature, add the sugar, and beat with an electric mixer until the mixture is creamy.

Add the egg to the sugar and butter mixture and beat until well combined.

Mix the flour, oats, salt, and baking soda, then add the dry ingredients to the sugar, butter, and egg mixture.

Finally, add the walnuts and chocolate chips, cover the mixture, and refrigerate for half an hour to rest.

Shape the dough into circles and press down slightly on top. Bake in a preheated oven at 375°F (190°C) for 10-12 minutes, then brown the tops.