Lettuce salad with blue cheese dressing

250g bacon, cut up and cooked till crisp
100g blue cheese
125g sour cream
3tbs mayonnaise
2-3tbs lemon juice
2 heads of iceberg lettuce, quartered
2 stalks spring onion
Some plain yogurt, to taste

For the dressing, crumble blue cheese into a bowl. Add sour cream, yogurt and mayo. Mix. Add lemon juice, to taste.

Plate the quartered lettuce and spoon dressing atop. Scatter bacon and spring onion.