Serves 4 as a starter; can be doubled.
2 cups low-sodium or homemade chicken stock, or mushroom stock
1/2 lb medium shrimp (31-40 size, or whatever you have), raw with the shells on
1/2 tsp sambal oelek, or to taste
6 mushrooms, sliced
1/2 tsp lime zest plus the juice of 1/2 lime
1 Tbsp fish sauce
A few cilantro leaves, for garnish (optional)
In a sauce pan, simmer the stock and shrimp for 10 minutes. Remove the shrimp and set aside to cool slightly. Add the sambal oelek, mushrooms, a tiny bit of the lime zest, half of the lime juice, and the fish sauce to the pot, and continue to simmer. Peel the shrimp and return them to the pot. After 30 seconds, remove the pot from the heat.
Taste, and adjust seasoning to your taste with more lime juice or sambal. Ladle into individual bowls, and top with the remaining lime zest and (optional) cilantro leaves.