Thoroughly rinse the quinoa under cold running water, drain well and set aside. Pour 1-1/2 cups reserved pear juice into a small bowl, add the cranberries and set aside to plump. Pour the remaining pear juice into a liquid measure and add enough water to make 13 cups. Set aside.
In a 5-quart saucepan, heat the oil over medium heat, add onions and cook until translucent. Add garlic and cook for 1 minute. Add quinoa and toast the grains until fragrant and slightly browned. Stir in the liquid and vegetable base and stir well. Add salt and pepper, reduce heat to a slow simmer and cover. When all of the liquid has been absorbed, remove quinoa from heat and allow to cool completely.
Drain the plumped cranberries and add them to the quinoa. Gently stir romaine, walnuts, diced pears, white balsamic vinegar and feta cheese into the room temperature quinoa. Toss to coat evenly, and chill until you are ready to serve. Serve at 41 degrees F or cooler.