40g (1.5 oz.) blue cheese [i like Roquefort best]
2 small cloves of garlic, grated into paste
1 tsp salt
1 rounded tsp mustard powder
1 tablespoon lemon juice
1 tablespoon vinegar
2 tablespoons olive oil
150 ml (5 fl. oz.) sour cream
2 tablespoons good quality mayonaise
2 minced spring/green onions
fresh ground black pepper

Blenderise this until smooth!