Tempura Pork with Finnadinni Sauce

Name: Tempura Pork with Finnadinni Sauce
Ingredients: 1 lemon, juiced; 1 cup soy sauce; 3 tablespoons white balsamic vinegar; 1 teaspoon granulated sugar; 1 jalapeno, seeded and diced; 1/4 cup loosely packed cilantro leaves; 1/4 cup loosely packed parsley leaves; 1/4 cup loosely packed basil leaves; 1/4 cup loosely packed mint leaves; 2 tablespoons minced garlic; 1/2 cup all-purpose flour; 1 tablespoon cornstarch; 1 tablespoon baking powder; 1 teaspoon salt; 1 egg; 1/4 cup soda water; 1 teaspoon rice wine vinegar; 2 cups buttermilk; 1 tablespoon Cajun spice; 1 pork tenderloin (1 1/2 to 2 pounds), sliced 1/2-inch thick on bias; Oil, for frying