Preheat oven to 425 degrees F. Toss the bell peppers, onions, and garlic with the olive oil, salt, and pepper on a large roasting sheet. Roast for 45 minutes, stirring every 15 minutes, or until vegetables have softened and are browned.
Towards the end of your roasting time, cook the orzo pasta according to the instructions. Drain and transfer to a large serving bowl.
Add the roasted vegetables, along with their juices and seasonings to the serving bowl and stir to combine.
Allow to cool to room temperature.
Squeeze the lemon juice over the pasta, add in the scallions, pignolis, and feta, then stir to combine again. Check seasonings and add salt and pepper to taste if necessary.
Put into a camping friendly container and store in the refrigerator until time to go.
When it is time to eat, sprinkle reserved basil over the top and serve.