Cilantro-Lime Shrimp Wraps

medium shrimp, peeled and deveined 

ground cumin 

Juice of 1 lime

freshly chopped cilantro, plus more for garnish

cloves garlic, minced 

extra-virgin olive oil, divided 

Kosher salt 

Freshly ground black pepper

Romaine lettuce, for serving

avocado, thinly sliced 

Sour cream, for serving