In a blender or food processor, combine milk with vegetable oil or melted butter, eggs, flour, sugar, and salt.
Blend at medium speed for 20 seconds, stop and scrape the sides of the blender jug with a spatula, and blend for 10 more seconds. Allow to mixture to rest for 20-30 minutes or overnight in the fridge.
Heat a 9-10 inch pan on medium high heat, and brush with a very small amount of butter, add ¼ cup of crepe batter to one side of the pan (preferably the top corner/opposite to the handle) and very quickly swirl to coat the pan with batter. If there are any holes, add a little more batter to cover them.
Cook until the sides of the crepe become golden, then flip and cook for 30 more seconds. Remove onto a clean plate, or cutting board or sheet pan. Repeat with the remaining batter (no need to add butter to the pan each time before adding the batter).
Serve with whipped cream, sweetened condensed milk, chocolate, fresh fruit, fruit compote, honey, ham and cheese, etc.