3 egg yolks
1 lemon (juiced or 2 tbsp. real lemon)
1 tsp. salt
1/4 tsp. dry mustard
1 tbsp. cider vinegar
2 c. vegetable oil

Process all ingredients, except the oil, for 60 seconds. Stop - scrape sides of bowl. Then add 1 tablespoon oil at a time, when incorporated, slowly add remaining oil in a thin steady stream until absorbed. Yields 2 cups.