Begin by preparing the salad base. Wash the romaine lettuce and purple cabbage, dry thoroughly, and chop or shred them into bite-sized pieces. Half the grape tomatoes and set them aside.
For the dressing, combine the mayonnaise, sour cream, and vegetable oil in a mixing bowl.
Add soy sauce, lemon juice, garlic salt, kosher salt, black pepper, and cayenne pepper to the mixture.
Whisk the ingredients together until you have a smooth and consistent dressing. Taste and adjust the seasonings if necessary. In a large salad bowl, toss the romaine lettuce, purple cabbage, and grape tomatoes together
Drizzle the dressing over the salad and toss again to ensure that the vegetables are evenly coated.
Right before serving, sprinkle the crushed nish nosh crackers over the salad for a delightful crunch.