Peel and thinly slice the shallots. Soak the glass noodles until soft, then cut into small pieces. Soak the wood ear mushrooms until soft, then slice into thin strips.

Shred the jicama and squeeze out excess water. Combine all filling ingredients and mix well. Make sure the filling is dry; if it's too wet, the spring rolls will lose their crispiness after frying.

When rolling the chả ram, the type of rice paper is key to getting a crispy result—not all rice papers work well! Place the filling on the rice paper, fold in the sides, then roll up. Don't roll too tightly or the rolls may crack when frying; don't roll too loosely or they'll absorb too much oil. Lightly brush the rice paper with diluted vinegar water before rolling to help prevent oil absorption and keep the rolls crispy longer.

I usually prepare the chả ram ahead of time and freeze them in a container. This makes them even crispier when fried. When ready to eat, fry the rolls straight from the freezer. Add enough oil to cover the rolls in the pan, and a little lime juice for extra crispiness. Fry until golden and crispy on all sides.

Remove the rolls and drain on a wire rack or paper towels. For the garlic chili fish sauce: crush garlic, chili, and sugar, then mix with fish sauce and fresh lime juice. For the sweet and sour fish sauce: mix sugar and water, then add lime juice, minced garlic, and chili. Adjust to taste as you like!