Heat the oil in a heavy pot like a Le Creuset over medium-high heat. Add the onion, lemongrass, galangal, and shallots to the pan and sauté for 10 minutes. It should be very aromatic.
Stir in the broth and lime zest, and bring to a boil. Reduce the heat to medium and simmer for 5 minutes.
Stir in the chili paste, shallot confit, lime juice, and sugar. Simmer for 5 minutes.
Add the angel hair pasta and the shrimp, and simmer for 3 minutes, or until the shrimp are opaque.
Thinly slice basil and cilantro for garnish.