Heat the annatto seeds in a small saucepan until slightly toasty. Add the olive oil and continue to heat for 3 to 4 minutes. Turn off and allow to cool. Now strain the oil and pour it over the shrimp. Turn the shrimp over and allow to marinate at least 10 minutes. Squeeze the lime over the shrimp and season. Keep cool until ready to cook and serve.;
Put the potatoes in a large pot and cover them with water. Cook about 15 minutes or until just barely cooked through. Now shock them in ice cold water to arrest the cooking. Drain and dice them into 3/4-inch sized pieces.
Mix the remaining ingredients in a separate bowl. Pour them over the cooked potatoes. Season to taste. Mix gently and allow to cool before serving.
Heat a medium large saucepan on medium high heat. Add the olive oil and butter. When the butter melts add the plantain slices. Allow them to cook until quite dark on each side.
Now add the chile and red onion and stir. When they are softened add the vinegar and reduce for 30 seconds. Now add the cream and reduce by 1/3. Stir as needed.
Blend all together and strain through a medium fine strainer. Set aside in a warm place.
To serve: Heat a grill or grill pan. Lightly oil grill to prevent sticking. Grill the shrimp until just done. Place the cool potatoes in the middle of each plate or on to a "family" styled serving platter. Spoon some of the prepared plantain crema on each plate, (or platter) and top with the shrimp. Serve. Can be garnished with fried plantain crisps and lime wedges.