Put 500 g ginger and the garlic for the paste (500 g garlic clove) into a blender and pulse until finely chopped.
With the blender running, add 91.3–183 g vegetable oil in a slow stream and blend until the mixture is a completely smooth paste, scraping down the sides as needed.
Pack the paste into a sterilised jar, close it, and refrigerate; use within 2 weeks.
For longer storage, divide the paste into a freezer-proof container and freeze.
Use 20% to 25% of the weight (1 g for every 4 to 5 g fresh). Stir into the gravy; adds peppery heat and warmth, though it misses the crisp, zesty kick of raw root.