Place the oil, popcorn and salt in a large pan. Make sure the sides of your pan are high to help the popcorn pop. I used a 3qt saucepan.
Cover with aluminum foil. Shake it a bit so that the kernels are coated with oil and salt. If you do not have foil, you can cover with a lid which has a vent on top ( or a regular lid but leave it slightly ajar) for the steam to escape.
Poke few slits in the top with a knife.
Place the pan over medium heat
and shake it constantly.
Continue shaking on and off until the popcorn finishes popping, approximately 2-3 minutes. This regular shaking helps in uniform popping. All that popping can push the foil on top, so it helps to secure it to the sides well. Can you see the slight bump on top? :)
Switch off flame, remove from the heat (if electric stove) and carefully remove the foil. Stir in any salt that is on the side of the bowl.
Slowly drizzle melted butter over the popcorn - you can add up to 2 tbsp for a buttery popcorn. This also helps the salt (and other seasoning that might want to add) to stick well to the popcorn.
and give it a shake once again.