I have lettuce, cucumber, tomato, what else can I add to make salad? partner with stroganoff thank you

Salad additions are about as numerous as stars in the night sky. You could add thinly sliced sugar snap peas, snow peas or blanched green beans for contrast. Sunflower seeds or other nuts like sliced almonds for crunch. Grated fresh beets, or cubed cooked beets, red onion, or radish slices, slices of olive - green or black. Chopped artichoke hearts, grated carrot, capers, bell pepper slivers, pickled veggies like from a jar of giardiniera, pickled pepperonici slices- your imagination is the limit really. Since stroganoff tends to be rich and soft textured, you want things that will crunch and contrast, and help cut through the richness of the cream. Nancy's suggestion to use a vinagrette or Russian type dressing is a good one, too.

If you can get them: dark safe lettuce (avoid romaine if in doubt), lots of fresh dill and parsley, maybe a few mushrooms and sliced cooked potatoes.
I would use as dressing, one if:
• oil and vinegar (to not compete with stroganoff sauce)
• sour cream dressing (to echo sauce)
• retro Russuan dressing with a few tablespoons of vodka (for the spirit of the evening)