In a large stew pot, melt the butter.
Add the onions, cooking until they are translucent and very soft, about 5 minutes.
Add the minced garlic and cook, stirring, until fragrant, about 30 seconds, being careful that the garlic doesn't burn.
Stir in the flour, coating all the onions. Continue cooking about a minute until the flour begins to brown, it will be very thick and gummy.
Very gradually, pour in the chicken stock. Pour about two tablespoons at a time (no need to measure, this is just an estimate), whisking it into the flour mixture. There should be no visible liquid between each pour. Continue this way until you use all the liquid, pouring more quickly at the end. This should take no more than about a minute or two.
Add the potatoes, corn, thyme, and bay leaves and increase the heat to high and bring to a boil (you are looking for big bubbles at the surface). Then reduce to a simmer (the lowest you can go heat wise and still see bubbles) and continue cooking for 20 minutes or until the potatoes are soft.
Stir in the shrimp and allow to cook for 3 minutes.
Stir in the cream, and let heat through for a minute. Season with salt and pepper to taste. The amount of salt you add will vary depending on your chicken stock. We added 1 teaspoon kosher salt and 1/4 teaspoon freshly ground black pepper at the end.