Penne with Courgettes and Lemon - Cooking like a Boss

900g 0.9kg 1.98lb 31.7oz penne	boil	drain	add	season
27 tbsp 0.405 l 405 ml 81 tsp 1.71 cup 0.713 pint double cream
11.2 tbsp 0.169 l 169 ml 33.8 tsp 0.713 cup 0.297 pint lemon juice
1800g 1 ⁴⁄₅kg 3.97lb 63.5oz courgettes	grate coursely	stir fry
9 clove garlic
225g 0.225kg 0.496lb 7.94oz butter
18 tbsp 0.27 l 270 ml 54 tsp 1.14 cup 0.475 pint fresh parsley	chopped