Bring a large pot of salted water to a boil over high heat. Add the potatoes and cook for 10 minutes. Add the corn cobs to the pot and cook until potatoes are tender and corn is cooked, about 6 more minutes. Remove potatoes and corn to a bowl and set aside. Clean pot.
Return the pot to the stove and add the chorizo and the poblanos, if using. Cook over medium-low heat, stirring, for 5-7 minutes. Add the potatoes back to the pot and pour in the chicken stock and LEMON BUTTER GARLIC SAUCE.
Add the prawns to the pot, bring to a simmer, and cover. Cook until prawns are plump and cooked through, 3-5 minutes.
Chop each corn cob into 4-5 pieces and add to the pot. Sprinkle with parsley, drizzle with additional warmed LEMON BUTTER GARLIC sauce and serve with lemon wedges.