Add about 1 – 1 ½ quarts of water to large pot and bring to a boil. On the side, add ice and cold water to a medium bowl.
Add ½ tsp salt to the boiling and stir to dissolve.
Add the basil to the water and boil for for just 15 seconds. The color should be bright green.
Drain the bail immediately and plunge into the ice bath to stop it from further cooking.
Remove the basil from the water. Gently squeeze the leaves to remove most of the water and drain on paper towels. Remove leaves from the stems if still attached.
Peel the garlic and roughly chop.
Add the basil leaves to a blender along with the the garlic, crushed red pepper, ½ tsp/3g salt, and oil.
Blend on medium speed, increasing speed until everything is pulverized.
Set aside for a minimum of one hour for flavours to mingle.
Store the oil in a sealed glass container in the fridge for up to 1 week.
Before serving, bring to room temperature.