Prepare noodles according to package directions, adding chicken soup base and oil to water.
Meanwhile, melt butter in a large heavy skillet over medium heat.
Add onions, and saut 5 to 7 minutes or until tender. Reduce heat to medium-low, and stir in Roquefort cheese, stirring constantly until cheese is melted.
Remove from heat, and stir in sour cream until blended and smooth.
Toss together Roquefort cheese sauce and hot cooked egg noodles.