Heat a skillet over medium heat and add 1 tablespoon neutral oil. When hot, add the minced garlic and ginger and sauté 20–30 seconds until fragrant but not browned.

Add the chopped onion and sauté 1–2 minutes until translucent.

Add the chopped mushrooms and cook 2–3 minutes until they release moisture and soften.

Add the shredded cooked protein, carrot, shredded cabbage, and bean sprouts. Stir-fry 2–3 minutes until vegetables are slightly softened but still have some bite.

Stir in 1 tablespoon soy sauce, 1/2 teaspoon oyster sauce, 1/2 teaspoon sesame oil, 1/8 teaspoon white pepper and 1/8 teaspoon salt. Toss to combine.

Mix 1 teaspoon cornstarch with 1 teaspoon cold water to make a slurry; add to the pan and cook 30–60 seconds until mixture becomes slightly glossy and binds. Remove from heat and spread onto a plate to cool for 5–10 minutes (filling should be warm but not hot when wrapping).

Assemble Rolls

Prepare a small bowl with the flour sealing paste: mix 1 teaspoon all-purpose flour with 1 teaspoon cold water until smooth.

Place one spring roll wrapper on a clean flat surface in a diamond orientation (one corner toward you).

Spoon about 1/3 of the cooled filling into the lower third of the wrapper, forming a log about 3–3½ inches long, leaving the side edges clear.

Fold the bottom corner over the filling snugly, tuck in the left and right edges toward the center, then roll away from you to the last corner. Brush the final corner with a little sealing paste and press to seal. Repeat to make the second roll.

Fry the Rolls

Pour about 1 cup vegetable oil into a medium heavy-bottomed skillet or pot and heat over medium-high until it reaches 350°F (175°C) or a small piece of wrapper sizzles immediately when placed in the oil.

Carefully add one or two rolls (do not overcrowd) and fry, turning occasionally, until evenly golden brown, about 2–3 minutes. Use tongs to rotate so all sides brown.

Remove rolls to a wire rack or paper towel-lined plate to drain excess oil. Allow to rest 1–2 minutes before serving so interior finishes cooking and wrapper crisps.

Make Dipping Sauce (optional)

Whisk together 1 tablespoon rice vinegar, 1 teaspoon soy sauce, 1 teaspoon water, 1/2 teaspoon sugar and 1/4 teaspoon chili flakes or a dash of sriracha until sugar dissolves. Adjust to taste.

Serve

Place the two spring rolls on a plate, garnish with cilantro or mint sprigs and serve with dipping sauce and lime wedges on the side. Enjoy while hot and crisp.