In a large stockpot set over medium heat, heat the oil and butter, about 2 minutes. Add the onion and garlic, and saute until tender, 5 to 7 minutes. Add the quinoa and corn, and saute for 3 minutes more. Add the stock, cream, potatoes, and Old Bay. Increase the heat to high and bring the mixture to a boil, then reduce the heat to medium-low and simmer, uncovered, until the quinoa and potatoes are tender, about 30 minutes.
Meanwhile, using kitchen shears, cut the bacon into small pieces and add to a medium skillet set over medium heat. Cook until brown and crispy, about 4 minutes, stirring constantly. Remove to a paper towel-lined plate to drain. Set aside.
Add the shrimp to quinoa and cook until they are pink and opaque, 2 to 3 minutes. Just before serving, add the parsley, green onions, and bacon.