3/4 lb large shrimp, peeled (tails left on) and deveined
3 tablespoons vegetable oil, divided
1 medium shallot, chopped
1 medium head napa cabbage, cut into 1-/4-inch slices
1/2 red bell pepper, cored, seeded and cut into thin strips
2 teaspoons fresh ginger, finely chopped
2 cloves garlic, very finely chopped
2 tablespoons tomato paste
1 teaspoon sriracha (or more to taste)
1 tablespoon soy sauce
1 tablespoon sugar
1 tablespoon freshly squeezed lime juice
5 cups low-sodium chicken broth
Salt and freshly ground black pepper
1 bunch (5 to 6) scallions, chopped
1/3 cup fresh cilantro, chopped
Put a large pot of salted water on to boil for the ramen. Discard the seasoning packet or reserve for another use. Cook the ramen until tender, drain and rinse with cool water to eliminate any excess starch.
Divide the ramen between 4 serving bowls and set aside.
Heat 1 tablespoon of the oil in a soup pot over medium-high heat. Add the shallot and sauté until caramelized, 2 to 3 minutes. Transfer to a small bowl and reserve for garnish.
Add another tablespoon of oil to the pan, then add the cabbage a handful at a time and sauté until slightly wilted, 3 to 4 minutes. Add the red bell pepper, cook for 1 minute additional, then transfer the mixture to a bowl and set aside.
Heat the remaining oil over medium heat, add the ginger and garlic and sauté until softened, 2 minutes. Stir in the tomato paste, sriracha, soy sauce, sugar and lime juice. Combine well, add the chicken stock and raise the heat to medium-high.
Simmer the broth, stirring occasionally, for 8 to 10 minutes to allow the flavor to develop. Season to taste with salt and pepper and add more sriracha if desired.
Stir in the shrimp and cook until pink and opaque, 1-1/2 minutes. Add the cabbage and bell pepper, cook for 1 minute more and remove the pan from the heat. Stir in the scallions and cilantro.
To serve, divide the shrimp and vegetables between the 4 bowls using a slotted spoon, then ladle a portion of broth into each bowl. Garnish with the caramelized shallots and serve immediately.