To Prepare Spicy Pickled Pineapple:
1. Thaw and drain 4 cups pineapple cubes. Set aside.
2. Place the rice wine vinegar, granulated sugar, 1/4 cup jalapeno, 1/2 Tablespoon kosher salt and 1/4 cup lime juice in a small sauce pot. Bring to a simmer, stirring until sugar dissolves.
3. Remove from heat and let cool to room temperature.
4. Place the 4 cups drained pineapple and cilantro into a large container.
5. Pour the vinegar mixture over the pineapple, making sure to cover it completely.
6. Cover tightly and refrigerate for at least 24 hours.
7. Can be stored for up to 2 weeks.
To Prepare Pineapple Mango Mojo Sauce:
1. In a medium saucepot, heat olive oil over medium heat.
2. Add garlic cloves and 1/2 cup small diced jalapeno and cook until fragrant, about 2 minutes.
3. Add oregano, cumin and 1 Tablespoon kosher salt. Cook an additional minute.
4. Add tomato sauce and cook until it reduces by half.
5. Add mango purée and 2 cups of pineapple cubes, 2 Tablespoons lime juice and cayenne.
6. Cook until heated through and the fruit becomes soft, about 10 minutes, stirring occasionally.
7. Transfer mixture to blender. Blend on high speed until the mixture is smooth.
8. Cool completely. Fold in the remaining 1 cup each of pineapple and mango cubes and reserve.To Prepare Cuban Mushroom Sandwich:
1. Wipe caps of mushrooms with damp paper towel. Remove stem and inner gills with a spoon. Marinate in 1-1/4 cups mojo sauce for at least 15 minutes.
2. Grill mushrooms over medium heat, while continuing to flip and baste with marinade mojo sauce to avoid drying out. Remove from heat and slice.
3. Slice the bread loaves in half.
4. Brush butter on top and bottom of bread coating edge to edge.
5. On the bottom heel, layer the sliced mushrooms onto the bread and cover with a single layer of julienned onions.
6. Drizzle 1/4 cup pineapple mango mojo sauce over mushrooms and onions, top with the bread crown.
7. Press sandwich on a panini press until bread is toasted and grill marks appear, then slice in half diagonally.
To Serve:
1. Transfer pressed sandwich to serving dish.
2. Plate sandwich with 1/2 cup spicy pickled pineapples and remaining mojo sauce on the side.