TO STEAM THE SHRIMP: Bring to a boil in a stainless steel pot all ingredients except the shrimp and the ice water. When water is boiling,add the shrimp and reduce heat to medium. Cook shrimp only until pink on the outside and still a bit gray at the middle.
They’ll finish cooking in the time it takes you to carry the pot to the bowl of ice water set in the sink. Pour contents through a colander, then place in ice water. Allow shrimp to cool completely. FOR THE SPRING ROLLS:
Place mai fun in a heatproof bowl and cover with boiling water. Let steep according to package directions, usually 3-5 minutes. Prepare the vegetables and add them all to a mixing bowl. Drain the mai fun well,pressing them against the sieve to remove as much water as possible.
Transfer them to a cutting board and roughly chop them. Add them to the mixing bowl. Add the lime juice and Sambal Olek. Remove shrimp from ice water and drain on paper towels. Pinch off the tails,then transfer them to your cutting board and roughly chop them also.
Add them to the mixing bowl and toss everything well to blend. PREPARE THE DIPPING SAUCE: Add all ingredients to the bowl of a food processor or blender. Purée until smooth. Taste and adjust seasonings as needed. Divide among dipping bowls.
To prepare rolls,work with one rice paper wrapper at a time. Place wrapper in hot water, pressing lightly so it is submerged. Let soak for 15 seconds or so,then gently lift and allow to drip for a few seconds. Transfer to a work surface, a wooden cutting board works well.
Arrange 2 cilantro stems across the middle. Place about 3 tablespoons of filling along the middle,leaving a border at each end. Fold the edge nearest to you over the filling,then fold in each end. Finally roll entire package over the opposite edge to seal.
Set on a serving platter with the seam side down and the cilantro stems visible through the surface of the wrapper. Repeat until all filling has been used. Just before serving, cut each roll in half through the middle with a diagonal slice that exposes the beautiful colors of the filling. Serve with the dipping sauce.