Green beans with lemon vinaigrette and parmesan

For some reason I tend to make beans mainly in winter. In the summer I veer towards grilled veggies or salads (and I am no fan of adding green beans to salads)....until, a few years ago, my mother told me about this recipe. I think it's the perfect way to make green beans in the summer. It's worth making this just for the color combination alone :-)

Ingredients (serves 2):

1 packet of green beans
1 lemon
1 handfull of grated parmesan 
olive oil 
salt, pepper

Preparation: 

1. Clean the beans and cook them for 5-7 minutes in boiling (salted) water. The beans should be "al dente", not soft or limp! Once cooked, drain the beans and chuck them in a bowl filled with ice cold water (best to add a few ice cubes). This not only prevents the beans from cooking further, it also turns the beans a lovely bright shade of green. 

2. For the vinaigrette just mix 4 tablespoons of olive oil with 2-3 tablespoons of lemon juice, some salt and some pepper. You want this to be on the sour side (the parmesan will partially compensate the acidity later on). 

3. Just before serving, mix the beans with the vinaigrette and sprinkle with the parmesan.