In a skillet over medium heat, heat about 1 tablespoon oil. Add onions and garlic and cook until limp.
Add diced pork and cook until lightly browned.
Add fish sauce and cook for about 1 minute.
Add water and bring to boil. Lower heat, cover, and simmer for about 7 to 10 minutes or until pork is tender and liquid is absorbed.
Add shrimps and cook, stirring occasionally, just until color changes to pink.
Add carrots and green beans. Cook, stirring regularly, for about 2 to 3 minutes or until vegetables are halfway done.
Add beans sprouts and cook, gently tossing to combine, for about 30 to 40 seconds or just until heated through. Season with salt and pepper to taste.
Immediately remove the vegetable mixture from heat and drain in a colander. Cover with film and refrigerate for a few minutes to completely cool.
Separate wrappers into individual sheets. On a flat working surface, lay wrapper like a diamond.
Spoon about 2 tablespoons of the vegetable mixture on the middle of the wrapper.
Fold the bottom pointed end of the wrapper over the filling. Fold side ends of the sheet inward and roll tightly into a log. Wet the pointed edge of the wrapper with a dab of water to completely seal. Repeat with the remaining vegetable mixture.
In a skillet over medium heat, heat about 2 inches deep of oil to 350 F. Add spring rolls seam side down and fry, turning once or twice, for about 2 to 3 minutes on each side or until golden brown and crispy.
Remove from pan and drain on a wire rack. Serve immediately with spiced vinegar dip.