Melt the butter in a large skillet over med-low heat. Add the onions and 1/2 tsp. salt and cook, stirring occasionally until deep golden brown, 30-35 min. Remove from heat and let cool. In med. bowl, mix together the onions, cream cheese, sour cream, chives, 1/4 tsp. salt and 1/8 tsp. pepper. Serve with chips.