Preheat deep fryer or 1/2 inch oil on stovetop to 375F degrees.
Cut off ends and peel the plantain.
Cut plantain into 1 inch thick pieces.
If using deep fryer: add the plantain and fry for 5 minutes. If using stovetop: fry for 5 minutes on one side and flip to fry 5 minutes on opposite side.
Take out of the fryer and smash plantains with a meat hammer or heavy pot. The plantains should be 1/4 inch thick after smashing.
Refry the smashed plantains for another minute. The tostones are now done!
Notes
Optional: If you eat garlic you could mix 1-2 cloves diced garlic with 1tbsp oil and pour over the tostones to coat when finished.