Rehydrate the mushrooms: In a mug or a cup, place 2 pieces of washed dried shiitake mushrooms, pour enough boiling water to submerge them completely, let soak for 10 minutes, then fish out the rehydrated shiitake mushrooms and slice thinly. Reserve 1 tbsp soaking water for sauce.
Rehydrate the vermicelli: In a larger bowl, place 1 serving of dried mung bean vermicelli, then cover completely with the rest of the boiling water, let soak for 5 minutes, then drain the water and toss the vermicelli in 1 tsp oil to keep from sticking.
Cook the aromatics: Heat 1 tbsp oil in a large frying pan over medium-high heat. Once oil is heated, add garlic and shallot, sautée for 1-2 minutes or until fragrant, mixing constantly with a spatula and taking care not to burn.
Cook the vegetables: Add the carrots, green beans, and sliced mushrooms into the pan, and toss or mix with spatula for about 3-4 minutes or until desired tenderness (although some crunch is good!)
Bringing everything together: Add the rehydrated vermicelli into the pan, along with the 1 tbsp shiitake mushroom soaking water, 1½ tsp low sodium soy sauce,1 tsp molasses, ½ tsp chili garlic sauce, and ¼ tsp pepper or more according to taste. Mix gently until sauce is evenly distributed, taking care not to break apart the vermicelli.
Final touches: Add a squeeze of lime juice, top with some sliced scallions, add more hot sauce or red pepper flakes, and your vermicelli is ready to serve!