Heat oven to 350 degrees. In a large mixing bowl cream together butter and sugars for 5 – 6 minutes with an electric mixer. Add egg and vanilla and mix until combined.
Add the flour, soda and salt and mix until blended. Add oatmeal and mix until thoroughly combined. Stir in nuts and chocolate chips by hand until incorporated. Dough will be very thick and stiff.
Using a tablespoon, drop heaping spoonfuls of dough on to an ungreased baking sheet. Bake 10 to 12 minutes. Remove from oven and let cool on a cookie rack.