For one large batch: Mix everything together, and drizzle with vinaigrette of choice.
For smaller amounts: For every 1 cup of leftover grain and 1 cup of roasted vegetables, add 2 to 3 tablespoons each of cheese and nuts/seeds. Drizzle with 1 1/2 – 2 tablespoons of your favorite dressing. Of course, you may certainly adjust the proportions to taste or based on the amount of specific ingredients you have on hand.
To build other delicious grain-based salads when roasted vegetables aren’t readily available, consider the following options: Add a combination of chopped apple or pear, diced raw carrots and celery, dried cranberries, chopped nuts and/or seeds, and crumbled cheese. Chopped cooked chicken, rinsed and drained garbanzo beans, or even leftover pork tenderloin are all complementary options that bump up the protein, too.
You can also think in terms of ethnic cuisine. For example, if in the mood for Mexican, add back beans, chopped red pepper, and corn. Avocado is best added just before serving. Red onion or sliced green onions add extra flavor to almost any grain-based salad.