Peel the plantains and cut them into 1-inch thick slices.
Heat vegetable oil in a frying pan over medium-high heat. Fry the plantain slices in batches until they are golden and slightly tender, about 2-3 minutes per side.
Remove the fried plantains from the oil and drain on paper towels. Use a plantain press or the bottom of a cup to flatten each slice to about 1/4 inch thick.
Return the flattened plantains to the hot oil and fry until they are crispy and golden brown, about 1-2 minutes per side.
Remove the tostones from the oil and drain on paper towels. Sprinkle with salt while still hot.
Enjoy your meal!