Trader Joe's is a great place to shop for anyone on a restricted diet. For my daughter, who is on SCD, we get fruit leathers, Larabars (some flavors, check the label), nuts that we roast or candy for snacks, great cheeses, frozen fish, dried fruit, etc.
It is the policy of Trader Joe's that everything in the product is listed on the label. People adhering to strict SCD will have to make their own determination about whether they truly trust in that. We decided that we will trust them, and have not had any problems so far with such products as mayonnaise and roasted nuts.
SCD school lunches for my daughter are either built around leftovers in a thermos, or lettuce wraps made with (homemade) egg salad, tuna salad, meat and cheese, etc. Some other things I put in my daughter's lunches for school: Sliced cucumbers with honey-mustard dip; celery sticks with almond butter; homemade fruit roll-ups; homemade meringues; SCD cookies; SCD white chocolates made with cocoa butter, coconut cream, and honey; cut up fruit with a dip made from SCD yogurt, honey, and cinnamon; homemade veggie chips (celeriac and butternut squash and beet, so far).