In a deep saucepan pour the Heavy Cream, Freshly squeezed Grapefruit Juice. Granulated Sugar and a pinch of salt. Stir over medium heat until combined.
Add Cornstarch and stir until it gets combined. After the Cornstarch gets combined, the filling will thicken. Once it starts to bubble, take it off the heat.
Grease a 9-inch Removable Bottom Tart dish with cooking spray or butter. Transfer the rolled Tart crust over the tart dish. Press the bottom and the sides. Line with parchment paper and fill it in with Pie weight or dried Beans or Almonds. Bake this Tart crust for 12-15 minutes at 350F or180C. Once Baked, get it out of the oven and cool it down.
Once the Tart crust has cooled down, pour the Citrus Filling in it. Evenly spread it using a spatula.
Decorate the Top with Slices Almonds, Chopped Pistachios, Sugar Dusted Cranberries, and Mint Leaves. Freeze for 2-3 hours or until completely set. Once it's set, cut into pieces and serve.