Savory Mashed Sweet Potatoes

Ingredients (9)

• 4 pounds sweet potatoes (about 7 small-to-medium), peeled and cut into 1" cubes
• 2 teaspoons salt, divided
• 1/3 cup finely sliced green onion, mostly green parts (from 1 bunch)
• 1/3 cup finely chopped fresh flat-leaf parsley
• 1 small-to-medium garlic clove, pressed or minced
• 1/4 cup sour cream*
• 3 tablespoons butter, cubed
• Freshly ground black pepper
• 1 teaspoon extra-virgin olive oil