1 head Boston lettuce
1 (5 oz.) bag spinach
3 slices bacon, diced
1/2 med. onion, diced
1/8 tsp. mustard
1/4 c. vinegar
1 egg
3 tbsp. sugar
3/4 tsp. salt
1/8 tsp. pepper

Tear greens into bite-size pieces. In skillet cook bacon over medium heat until browned. Dry on paper towel. In drippings cook onions until tender, 5 minutes. Add vinegar, sugar, salt and mustard. Continue cooking until sugar is dissolved.

In small bowl, beat egg slightly. Stir in small amount of hot mixture then pour into remaining hot mixture, stirring to prevent lumps. Cook, stirring constantly until sauce thickens. Pour over greens. Add bacon bits and toss well.