In a large saute pan over medium-high heat, add 2 tablespoons of oil. Add the onions, carrots, mushrooms, garlic, sriracha, soy sauce and lime juice. Cook until the vegetables are softened, stirring frequently.
Remove from heat and transfer to a medium-sized bowl. Add the cilantro and allow the mixture to cool.
In a small bowl combine the egg white and cornstarch. This will be used as an egg wash.
Preheat oil in a deep-fryer to 350 degrees F.
On a flat work surface, lay out 1 egg roll wrapper. Add a layer of vegetables to the lower part of the wrapper and top with 1 strip of tuna. Brush the sides of the wrapper with egg wash and roll up tightly once, bringing the sides over, and then continue to roll until finished. Put the roll on a large plate and repeat with remaining wrappers and filling.
Fry the egg rolls, in batches, until golden brown, about 2 minutes. Remove egg rolls to paper towels to drain. Transfer the rolls to a serving platter, garnish with scallions and orange slices and serve with Citrus Dipping Sauce.
In a small bowl, mix all ingredients and reserve.