Heat a large pot or dutch oven over medium heat. Once hot, add oil or water.
Add lemongrass (optional) and onion and sauté for 5 minutes, stirring occasionally. The onions should become translucent and soft and slightly browned.
Add fresh ginger, chili peppers, shiitake mushrooms, garlic, and curry paste (which is added to substitute for fresh makrut lime leaf and lemongrass) and stir. Sauté for 4-5 minutes, stirring occasionally.
Add vegetable broth, coconut milk, a few slices of lime peel, diced (drained) tomatoes, coconut aminos, and coconut sugar and stir to combine. Bring back to a boil, then reduce heat to a simmer, cover, and cook for 10-15 minutes.
Add the lime juice and stir. Simmer for a few more minutes. Then taste and adjust flavor as needed, adding more lime for acidity, coconut sugar for sweetness, coconut aminos (or salt) for saltiness / depth of flavor, or coconut milk for creaminess.
Optional: Remove lemongrass and lime peel before serving using a slotted spoon or fork (or just eat around it).
Serve as is, or over zucchini noodles, kelp noodles, or cooked rice noodles. You could also serve it over white rice or brown rice. Garnish with fresh cilantro for a pop of color (optional).
Store leftovers covered in the refrigerator up to 4-5 days, or in the freezer up to 1 month. Reheat on the stovetop, covered, until warmed through.
*Adapted from the lovely Evergreen Kitchen! *This version is not traditional, but is our inspired, plant-based take. You can find a more traditional recipe from Hot Thai Kitchen here. *Nutrition information is a rough estimate calculated with lesser amount of coconut aminos and coconut sugar and without optional ingredients.