If your shrimp is frozen or unpeeled, make sure you thaw and peel the shrimp before beginning. Juice half of the lemon (you'll need about 2 Tbsp juice) and slice the rest of the lemon for garnish.
Mince the garlic. Add the garlic to a deep skillet along with the butter and sauté the garlic over medium heat for 1-2 minutes.
Add the rice and continue to sauté for 1-2 minutes more. You should hear the rice begin to snap and crackle a little as it sautés in the hot butter.
Carefully add the chicken broth, 2 Tbsp lemon juice, water, Tony Chachere's (or seasoning salt), and chopped parsley. Stir to combine.
Place a lid on the skillet and turn the heat up to medium-high. Allow the broth to come up to a full boil. Once it reaches a boil, turn the heat down to low and let it continue to simmer for 10 minutes.
After simmering for 10 minutes, most of the broth should be absorbed by the rice. Lift the lid briefly in order to scatter the shrimp over the surface of the rice. Replace the lid and allow the skillet to continue to cook over low for an additional 5 minutes.
Remove the skillet from the heat and allow it to rest, lid in place, for an additional five minutes. After resting, lift the lid. The shrimp should be opaque and pink.
Use a fork to carefully fluff the rice and partially stir the cooked shrimp into the rice. Add the leftover lemon slices and sprinkle with extra chopped parsley, if desired. Serve hot.