Pat steaks dry with a paper towel. Sprinkle with 1 teaspoon garlic powder and ½ teaspoon salt on both sides of the steaks, place on plate and set aside.
Pour enough oil into a heavy bottom fry pan or cast-iron skillet to coat the entire pan and heat it up over medium heat.
Carefully place the plantain slices in the pan. You may need to do this in batches. Fry the plantains in until tender and just golden, 8-10 minutes each side. Transfer to a paper towel-lined plate to drain.
Using a plate or small cutting board, press the plantain slices between parchment paper. Return the pressed plantains to the oil and fry until golden and crisp, about 2-3 minutes. Transfer to a paper towel-lined plate to drain then season with salt.
Heat the same skillet over medium-high heat and more oil, if necessary. Place the steak in the skillet. Cook the steaks for 3 to 4 minutes each side, or until the internal temperature reaches 135 degrees. Set aside on a plate to rest for 5 minutes.
To assemble the sandwich, top two plantain slices with steaks, avocados, onions, lettuce, sauteed mushrooms and then top with the remaining plantain slices.
Recipe by Autoimmune Wellness at https://autoimmunewellness.com/puerto-rican-plantain-sandwich-jibarito/