Smashed Peas with Mint Butter

Cook peas with water and ½ teaspoon salt in a 5-quart heavy pot over moderate heat, covered, stirring occasionally, until heated through and tender, about 8 minutes.

While peas cook, stir together butter, mint, parsley, pepper, and remaining ¾ teaspoon salt until combined well.

Pulse peas (with cooking water) in 2 batches in a food processor until coarsely puréed, transferring to a large bowl. Stir in herb butter until melted.