Preheat your grill or broiler to medium-high heat. Roast Hatch chiles for 10-15 minutes until blistered.

While chiles cool, dice Roma tomatoes and chop sweet onion and cilantro.

Peel chiles, remove seeds, and chop. Add to the mixing bowl with tomatoes, onion, and cilantro.

Add lime juice, salt, and pepper to the bowl, then stir to combine.

Taste and adjust seasoning if needed. Serve immediately or let sit for 30 minutes to meld flavors.