The meatball recipe is scalable. This makes about 20, and I would double it to make it worth your time, and just freeze the portion you don't plan to use right away.
Greekish Meatballs
1 lb. ground lamb
1 egg, whisked
1 T. chopped fresh mint (or 1 Tsp. dried)
1 piece of bread, torn/shredded (or a handful of breadcrumbs)
1 Tsp. cumin
1/2 Tsp. cinnamon
zest of one lemon
3 garlic cloves, minced
Lemon juice (just a squeeze)
S+P
Combine everything and form into itty bitty meatballs. I use a melon scoop thing, or you could just do it by hand, but I like them uniform. I cooked these in a large skilled with olive oil, but it was messy. Next time I will likely cook them in the oven. If you don't plan to use them within a few days, wrap them well and freeze them.
The dressing should be tzatziki. That would make this legitimately Greek. But I didn't have any on hand, and it is pain in the arse to make so THAT wasn't happening, so a light yogurt dressing was a delicious substitute. I used 2% Fage greek yogurt, lemon juice (the rest of the lemon from the meatballs), and salt. Whisk well, use immediately.
The rest of the sandwich is self explanatory - whole wheat pita (Greek pita, NOT the kind with a pocket), tomatoes, greens, and if I'd had any, I would have included red onion slices. Alas, I was out. To make this quick dinner I simply microwaved the meatballs I'd made ahead (30 seconds), smeared the yogurt dressing on the pita, then added the greens and tomatoes. It was divine! Even the baby at it.