Mushroom and spinach tagliatelle

Ingredients

   1 tbsp olive oil

   bunch spring onions, finely sliced

   2 garlic cloves, finely chopped

   10 button or chestnut mushrooms, finely sliced

   200g fresh spinach, washed

   1 tbsp plain flour

   1 x 200ml7fl oz tub crème fraîche

   salt and freshly ground black pepper

   300g/10½oz dried tagliatelle