Cook the glass noodles: Bring a medium (large) saucepot of water to a boil. Add the glass noodles and cook until just tender, eight to 10 minutes. Drain and rinse with cold water.
While the noodles cook, prepare the soup.
Prep the ingredients; cook the soup: Trim the ends from the radishes; cut the radishes into quarters.
Rinse the shrimp, then drain on a paper-towel-lined plate and pat dry.
Juice half the lime; cut half into wedges for garnish. (Juice 1 lime; cut 1 lime into wedges.)
Coarsely chop the cilantro for garnish.
In a medium (large) saucepot, combine the radishes, vegetable broth, tomato-ginger soup base, and two cups water. Season with salt and pepper, and bring to a boil. Reduce to a simmer, add the shrimp, and cook, stirring occasionally, until the radishes are tender and the shrimp are firm and cooked through, two to three minutes for regular shrimp, three to four minutes for jumbo shrimp. Remove from the heat, stir in the arugula, and season to taste with lime juice, salt and pepper.
Serve: Divide the glass noodles between individual bowls. For each portion, ladle one cup soup over the noodles, plus more, if desired. Garnish with the cilantro and as much sambal oelek as you like and serve with the lime wedges.
Servings 2