In a small saucepan place the plantain and boniato (or yam) and add cold water to cover by 1 inch. Put over high heat and bring to a boil, then reduce temperature to medium and simmer until tender, about 8 minutes.
Drain water from the plantain and boniato, bringing them back into the same saucepan. Mash them together with potato masher or fork, then stir in cumin, 1/2 teaspoon butter, and the Mexican crema. Season with salt and freshly ground black pepper. Set aside.
Place a chicken breasts into a large Ziploc bag, close the bag almost all the way, then flatten the meat to a thickness to between 1/2-inch and 1/4-inch; repeat with remaining pieces.
Season both sides of the chicken with salt and black pepper. Place a chicken piece on a flat work surface and top with a slice of prosciutto. At one end of the prosciutto-covered chicken place 1 tablespoon of the plantain mixture shaped into a rectangular “log.” Roll up the chicken and secure with a toothpick. Repeat with remaining chicken pieces, prosciutto, and plantain mixture. Dredge the stuffed chicken in flour to coat.
In a large heavy skillet over medium-high heat, melt the butter together with the olive oil. Add the stuffed chicken pieces to the skillet and brown chicken on all sides, about 5 minutes total.
Add 1/4 cup no-salt chicken stock/broth or water to the skillet and reduce heat to low. Cover skillet and let simmer until the chicken is cooked through, about 15 minutes.
Prepare a warm serving platter and transfer the cooked stuffed chicken pieces to the platter. Remove the toothpicks from the pieces.
Add the fresh lemon juice to the drippings in the skillet and increase temperature to high. Let cook for 1 minute, stirring to get the browned bits from the bottom of skillet. Pour the sauce over the stuffed chicken pieces and serve.
Adapted from May 2007 Bon Appétit and Daisy Martinez’s recipe for Chicken Thighs Stuffed with Plantain and Serrano Ham.
Note: lime juice for the sauce would also be very nice, and a completely different taste! You can also substitute chicken thighs for breasts.