Bring water and wheat berries to a boil in a saucepan. Reduce heat to medium-low, cover, and simmer until the wheat berries are tender, 45 minutes to 1 hour.
Drain any excess water and cool.
Preheat oven to 375 degrees F (190 degrees C).
Spread walnuts onto a baking sheet.
Bake walnuts in the preheated oven until toasted and fragrant, 5 to 10 minutes.
Remove pan from oven and cool.
Whisk canola oil, raspberry wine vinegar, raspberry preserves, mustard, oregano, and black pepper together in a bowl until vinaigrette is smooth. Measure 1/2 cup vinaigrette and store remaining vinaigrette in an airtight container in the refrigerator for another use.
Combine wheat berries, walnuts, pear, Gorgonzola cheese, cranberries, and green onions in a large bowl.
Drizzle 1/2 cup vinaigrette over wheat berries mixture; toss to coat. Refrigerate for flavors to blend, about 30 minutes.