Place salmon on a flat work surface. Roll the thin ends into the thicker end and tie with cooking twine. Brush with sunflower oil. Transfer salmon rolls into a glass dish. Top with juice and zest of 1 lime. Season with salt and pepper. Cover with plastic wrap; refrigerate until well marinated, about 2 hours.
Place remaining lime juice and zest, chile peppers, 1 tablespoon olive oil, sunflower seeds, and garlic in a food processor. Puree, pouring the rest of the olive oil in gradually, until pesto is blended and thick.
Preheat an outdoor grill for medium-high heat and lightly oil the grate. Place salmon rolls on grill. Cook until salmon flakes easily with a fork, 4 to 5 minutes per side. Divide salmon across serving plates; spoon pesto on top.