Soften glass noodles in hot water until softened, about 10-15 minutes, then drain.
Preheat a pot over medium heat, then add oil and fry onions until translucent.
Add red curry paste, lemongrass, and fry until fragrant. You may need to add a little water/broth to help the paste dissolve. Add the rest of the broth (or water + mushroom powder) and bring water a boil.
Add celery and cook for about 3-5 minutes, until just tender with a tiny bit of crunch. Then add noodles and cook for another 3-4 minutes under tender.
Add snap peas and chopped tomatoes and stir, cooking for another 2-3 minutes. Stir in baby spinach until just wilted.
Remove from heat and serve with half of a juiced lime in each bowl. Top with fried marinated tofu, and enjoy!