In a medium bowl add the strawberry jam and balsamic vinegar. Whisk in the olive oil and season with salt and pepper to taste. Set aside or refrigerate until ready to use. (Bring to room temp. before using)
In a large salad bowl toss the strawberries, red onion, and lettuce together. Pour dressing over lettuce and toss to coat evenly. Add nuts and cheese and toss. Serve.