Fried Ripe Plantains (Pl?tanos Maduras Fritos ? Puerto Rico)

4 medium very ripe (nearly all black) plantains
4 tablespoons butter, divided
Salt or garlic salt, to taste (optional)
2 limes, cut into wedges (optional)

Peel plantains as you would a banana, then cut them on the diagonal into 3/4-inch slices. Heat 2 tablespoons butter in a large nonstick skillet over medium heat. Saut? half the plantain slices in a single layer until they are quite brown on the underside, about 4 minutes. Flip them over with a spatula and saut? until brown on the other side, about 3 minutes. Leaning the slices against each other if necessary, stand each plantain slice on one of its edges in the skillet and saut? for 30 seconds. Next stand the slices on their opposite edges and saut? an additional 30 seconds.

Remove one slice from the skillet, cut it in half, and check to see that the plantain has lost its pale yellow, white, or pink tinge and has turned yellow all the way through. If so, the plantains are ready. If not, continue saut?ing them for another minute on the sides that are the least brown.

Gently remove fried plantains from the skillet with a spatula and pace them on paper towels to drain. Add remaining butter to the skillet and saut? remaining plantains in the same fashion. Arrange fried plantains in one layer on a large serving plate. Sprinkle them with salt or garlic salt, if desired, and serve at once with lime wedges or plain.

Serves 6 to 8 as a side dish or appetizer.