Make the strawberry salad dressing: Blend all ingredients until smooth.
Prepare the salad ingredients: Slice the strawberries length-wise. Thinly slice the red onion. Wash the spinach. Chop the pecans.
Serve: Place the greens on plates and top with all ingredients, then drizzle with the strawberry vinaigrette salad dressing (about 2 tablespoons per serving). Refrigerate the remaining dressing for up to 1 week.