Cover the bottom of a 9 by 9 pan with aluminum foil that has been sprayed with cooking spray. (To use a cookie sheet double the recipe.)
Combine the butter, sugar, and salt in a heavy saucepan. (don't use a cold saucepan...let it warm a bit)
Bring to a boil over medium heat…stirring constantly. (don't skip the stirring!) Bring it to a boil gently and continue stirring often (watch out for it sticking)!
Cook until it darkens in color about 10-20 minutes. (technically that is 285 degrees…we guess) (Update: My daughter wanted me to mention a trick to know if it's done...
If you drop some of the mixture into ice water, wait a bit for it to cool, and it stays hard when you take it out of the water...it's done.)
When your butter and sugar mix gets to the right color pour into the pan.
Sprinkle the top with the chocolate chips.
Leave for a minute to soften. Spread.
Put the nuts on top. Push those nuts in a bit so they stick.
Pop into the fridge until set.