In a large pot, heat the oil for the sauce, then throw in onion, jalapeños, garlic, ginger, and lemongrass. Stir and let sweat for 5 minutes.
Add chopped spinach, basil, and cilantro to the pot and wilt 2 minutes.
Add curry paste, salt, zest, and lime juice. Stir until aromatic, about 2 minutes.
Pour in coconut milk and blend with a immersion blender until smooth.
Add 2 tbsp corn starch to the sauce, then blend again.
Toss in the carrots, eggplant, peppers, shiitakes, and tofu.
Turn heat down to low, cover, and let simmer 30-40 minutes.
While the curry is simmering, cook rice noodles according to package directions.