Make sure the shrimps are very cold. If you have time, put them in the freezer for about 20 minutes.
Cut lemongrass stalks into 4 to 4 1/2-inch sticks. If the outer layer is dry, peel it off. Make a few slits along the lemongrass to make it easier to release the aroma. You can watch the video in the post to see how to do this step.
Add shrimps to the bowl of a food processor. Also add garlic, shallot and ginger. Pulse a few times until shrimps are coarsely chopped.
Add salt, black pepper, fish sauce, olive oil and cornstarch to the food processor bowl and process until smooth.
Check if the shrimp mousse is still cold. If not, chill in the refrigerator. Use a spoon to mix the paste a few times. Very lightly oil your hand and use a tablespoon (or slightly more) of shrimp mousse to wrap around the top part of each lemongrass stick.
Place a fry pan with a generous amount of oil over medium heat. Once the oil is hot, add shrimp sticks and fry until golden. You can also grill them.
Serve hot with sriracha sauce (or Vietnamese nuoc cham dressing or Thai chili sauce), lettuce and fresh herbs. You can also add some rice vermicelli noodles to the serving plate.