In a small saucepan on medium heat, cook together the sugar, vanilla bean paste, ¼ cup water, and 200 g small diced strawberries. Cook for about 10 minutes until bubbly, thick and strawberries are mostly broken down
Right before the 10 minutes are up, in a measuring cup, create a cornstarch slurry by mixing together ½ cup of water and ¼ cup of cornstarch. Whisk the water and cornstarch together until no clumps of cornstarch remain. Add in the cornstarch slurry and cook for 2-3 more minutes until slightly thickened and glossy
Remove from heat and add the strawberries and lemon juice and zest
Let it cool for about 15 minutes before pouring over the cooled cheesecake. Set in the fridge for 2 hours until set. Slice and serve