Petits Pois à la Française (French style peas)

This image really does not do justice to this dish.  In the past 5 days since trying this recipe, I've made it three times for our family dinner! It's absolutely delicious, healthy and easy to make.  I love the combination of vegetables; that type of vibrant green produce immediately transports me to a wholistic, country fresh place. 

Ingredients
50g butter
16 baby onions or French shallots
500g frozen peas
250g finely shredded iceberg lettuce
handful of fresh (Italian) flat-leaf parsley leaves
1 tsp caster sugar
1/2 cup chicken stock
1-2 tbsp plain flour

Method
Melt 30g of the butter in a large saucepan or frypan.  Add the onions and cook, stirring for 2-3 minutes.  Add the peas, lettuce, parsley and sugar.  Pour in the stock and stir well.  Cover the pan and cook over medium-low heat for 15 minutes. Stir occassionally so that the onions are cooked through evenly.  Mix remaining butter into pan.  Add small amounts of the flour to the vegetables; stirring until the juice thicken.  Serve.