Over medium heat, add the of vegetable oil to a caldero or dutch oven pot and heat through.
Add the tocino, ham steak and the ham hock (if using). Cook for a few minutes until slightly browned.
Add the sofrito, sazon, chicken bouillon, oregano, bay leaves, garlic, olives and stir well. Cook for about two minutes. Add the can of gandules including the water they came in followed by the water and stir. Allow the water to come to a low boil.
Using a food processor with the grating disk attached, grate the plantain. Then remove the shredded plantain and grating disk. Attach the chopping blade and return the shredded plantain to the bowl. Blend until a puree forms. Note: You could also use a box grater on the finest side.
Add the plantain to the pot and stir.
Add the rinsed rice and stir. Season with salt to taste. Check to make sure there's enough water to cook the rice. Tip: You will know you have added enough water when a large spoon, placed on top of the rice, is nearly fully submerged by the water when the spoon is laid on top. Note: If using long grain rice, you will need to add an additional cup of water. (If doing the spoon test, the spoon will now be fully submerged in water.) Increase the heat to medium-high and let the water almost completely evaporate, about five minutes.
Using a pair of scissors, cut one to two pieces of plantain leaves to about a 10x10 size. Cut off the "rough" membrane of plantain leaves, then rinse the pieces with soapy water and wipe dry. Set aside.
Stir the rice gently with a large spoon and cover the top of the rice with the plantain leaves. Then cover the pot immediately with a lid, and reduce the heat to medium-low. Tip: When stirring the rice, do not stir so hard that the "pegao" (crispy rice) forming at the bottom of the pan gets distributed into the rest of the rice. Let the rice cook for fifteen minutes on medium-low heat without disturbing it.Note: Once you've stirred the rice and covered the pot, resist the urge to remove the lid until it's time to check and stir again. Lifting the lid will disrupt the cooking process, causing the rice to stay undercooked and grainy. After fifteen minutes, remove the lid and stir the rice again. Cover the pot again and continue cooking for another fifteen minutes.
After fifteen minutes, remove the lid and give the rice a final stir. The rice is done. Sprinkle chopped cilantro on top for garnishing and extra flavor. Could also top with a few pieces of the pimiento strips for presentation and flavor.