Penne with Courgettes and Lemon - Cooking like a Boss

200g ¹⁄₅kg 0.441lb 7.05oz penne	boil	drain	add	season
6 tbsp 0.09 l 90 ml 18 tsp 0.38 cup 0.158 pint double cream
2.5 tbsp 0.037 l 37.5 ml 7.5 tsp 0.159 cup 0.066 pint lemon juice
400g ²⁄₅kg 0.882lb 14.1oz courgettes	grate coursely	stir fry
2 clove garlic
50g 0.05kg 0.11lb 1.76oz butter
4 tbsp 0.06 l 60 ml 12 tsp 0.254 cup 0.106 pint fresh parsley	chopped