Boil water in a kettle and pour 500ml of that into a ceramic bowl.
Add the rolled oat in the boiled water and give it good mix. Leave it covered for about 30 minutes.
Transfer the oat mixture into a beaker and add in the oil and the salt. Pulse with a hand blender until smooth.
Run the blended oat through a sieve over a mixing bowl. The rough bits get caught in the sieve and the smooth liquid goes down in the bowl. *If you want smoother texture, sieve 2 or 3 times. I did it 2 times.
Keep in the fridge in a glass jar for up to 10 days :)
Notes
Alternatively you can use a cheese cloth to do a squeezing method. That way, you will get smoother cream without the brown residue from the oats.