Thick, Soft, and Chewy Chocolate Chip Cookies

Mix flour, baking soda, and salt in a small bowl.
In a separate bowl, beat butter and shortening until creamy.
Add sugar and vanilla and beat with a mixer on medium speed until well blended.
Beat in eggs, one at a time, mixing well.
Add flour mixture, and beat slowly to incorporate, then beat to blend well.
Stir in chocolate chips and nuts.
Drop batter in 2-tablespoon portions about 2 inches apart on baking sheets.
Bake in a 375°F preheated oven until edges of cookies are brown but an area about 1 inch wide in the center is still pale, about 10 minutes.
If using 2 pans in 1 oven, switch positions at half-time.
Let cookies cool on pan about 5 minutes, then transfer to racks with a spatula.
Serve warm or cool.