Start by heating a pot on the stove on low heat. Add in the half and half and sugar. Give this a stir.
To another small sauce pan add the cold water and the envelope of gelatin. Heat the gelatin on low heat until it is dissolve. This does not take long. Once dissolved, remove from the heat.
Bring up the temperature of the half and half to about medium to medium high. The goal is to not bring this to a boil. Slightly before it boils, remove it from the heat and add in the gelatin mixture and give a good stir. Add in the vanilla and stir.
Pour, dividing, into ramekins. Fill about 75%. You should be able to fill about 6-8 ramekins.
Let the ramekins get to room temperature, then place them in the refrigerator for at least 6 hours, but best if overnight. Waiting on this is horrible.
Go ahead and make the strawberry glaze.
Stir the water and corn starch and make a slurry.
Blend the frozen strawberries and water. Pour this through a fine mesh strainer and use the back of a spoon to press through the strainer over a bowl. Patience is required here and you will probably have to keep stirring and pressing through the strainer. Reserve both.
To a small sauce pan, add the reserved strawberry liquid. Add in the corn starch slurry. Stir well and bring up the heat and stir until the sauce slightly thickens. Pour into a container and place in the refrigerator, along with the reserved puree if you are wanting to use.
After the very long six hours or if you have the patience and can wait overnight, take a ramekin out.
Run a knife around the edge of the ramekin and once completely around, gently yet swiftly turn it onto your serving plate (heck otherwise pour some glaze on it, along with some fresh strawberries and dig in).
It wiggles, people! Take the strawberry glaze out and use a spoon to drizzle all over that panna cotta. Arrange some fresh strawberries alongside and get to town.