Creamy lemon veg pasta

Name: Creamy lemon veg pasta
Ingredients: 175g/6oz dried pasta, such as orecchiette, casarecce or penne; 1 tbsp olive oil; 1 shallot, finely chopped; 2 garlic cloves, grated; pinch dried chilli flakes; 1 tsp vegetable stock, or ½ vegetable stock cube, crumbled; 150g/5½oz cavolo nero, stems removed and leaves roughly chopped; 150g/5½oz spring greens, stems removed and leaves roughly chopped; 50g/1¾oz crème fraîche; 1 lemon, finely grated zest; 20g/¾oz Parmesan (or alternative vegetarian hard cheese), finely grated; salt