To make the Thai Coconut Broth: Place the vegetable stock, coconut milk, ginger, shallot, garlic, lime zest, lemongrass, and salt in a medium-sized saucepan. Bring it to a boil on high heat, then turn it down to medium-low and let it simmer for 30 minutes.
Strain the broth into a bowl and discard the solids. Set the broth aside.
Meanwhile, start working on the chowder ingredients. Pat the salmon dry using paper towels. Season with salt and pepper.
Heat the oil in a stock pot over medium heat. Add in the onion and peppers and cook, stirring frequently, until translucent, 4-5 minutes. Add in the grated ginger and garlic and cook for approximately 1 minute.
Add in the broth that was set aside along with the second can of coconut milk. Bring the mixture to a boil and let it simmer for 15 minutes.
Add in the broccoli florets in the last 5 minutes of the simmering time.
At the last minute, add in the cubed salmon and let it cook for a minute, and turn the heat off. It should continue to cook with the help of the residual heat.
Stir in the lime juice and maple syrup. Taste for seasoning and add more if necessary.
Garnish with chopped scallions, sliced jalapenos, and torn fresh cilantro leaves. Serve with lime wedges on the side.