Summer draws New Englanders to decks, porches, picnic tables, and beach blankets with all kinds of light fare. When we asked readers to send their favorite dishes into The Recipe Box Project, we found ourselves with a vegetarian picnic basket. Add grilled chicken, hot dogs, or burgers, if you like, or skip the meat and prepare piquant red lentil burgers slipped into pita pockets. You’ll want a traditional creamy potato salad on your plate, with plenty of paprika and parsley, or a pink-tinted Dutch version with beets and apples. Cabbage slaw with a sweet vinaigrette is seasoned with mustard and celery seed; it marinates overnight and still comes out crunchy. A lemony chickpea salad will add more protein to the table. Fill out the menu with a custardy caramelized onion pie.