Brine the Shrimp (OPTIONAL): In a medium bowl, dissolve 1/2 teaspoon of baking soda and 1/2 teaspoon of salt in 1/2 cup of cold water. Add the shrimp and let them soak for 15 minutes to improve their texture and make them extra crunchy. After soaking, rinse the shrimp well under cold water, pat them dry with paper towels, and set aside.
Prepare the Sauce: In a small bowl, whisk together the Kung Pao sauce ingredients. Set the sauce aside for later.
Cook the Shrimp: Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat. Add the shrimp in a single layer, season lightly with salt and pepper, and cook for 2-3 minutes, or until they are just pink and opaque. In the last 30 seconds, add 1 teaspoon each of fresh minced garlic and ginger, stirring to release their aromas. Transfer the shrimp to a clean bowl, leaving any oil behind in the skillet.
Sauté the Vegetables: Add the remaining tablespoon of oil to the skillet along with the remaining teaspoon of garlic and ginger. Sauté for about 30 seconds, then add the bell peppers and celery. Cook for about 3 minutes, stirring occasionally, until the vegetables are just tender and slightly charred.
Combine and Sauce: Return the shrimp to the skillet, leaving any accumulated juices in the bowl. Pour in the prepared sauce and add the peanuts, stirring everything to coat. Cook for 1-2 minutes, or until the sauce thickens slightly and the ingredients are well glazed.
Finish and Serve: Remove from heat, stir in the green onions, and give the dish a final toss. Serve hot with steamed rice or noodles for a complete and flavorful meal.