Heat your large wok or skillet over medium-high heat until shimmering. Add the oil and swirl to coat the surface. Once hot, add the shrimp in a single layer and cook for 1-2 minutes per side, until they turn bright pink and are just opaque. Remove the shrimp and set aside.
In the same pan, add a little more oil if needed, then toss in the minced garlic and grated ginger. Stir constantly for about 30 seconds until fragrant—smells toasty and warm. Add the frozen vegetables directly from the freezer, stirring well to coat them with the aromatics. Cook for 3-4 minutes until heated through and slightly crisp.
Return the cooked shrimp to the pan. Pour in the soy sauce and a splash of water or broth. If you want a thicker sauce, stir together the cornstarch with a teaspoon of cold water to make a slurry, then add it to the pan. Cook for another 1-2 minutes, stirring constantly until the sauce is glossy and coats all the ingredients.
Turn off the heat and stir in the lemon juice or rice vinegar for a bright finishing touch. Taste and adjust seasoning if needed. The sauce should be shiny and cling to the ingredients, with a vibrant aroma and a balance of savory and tangy flavors.
Serve the stir fry immediately over steamed rice or noodles. Garnish with sliced green onions if desired, and enjoy the warm, savory bites with a hint of brightness.
