A pickling brine gives these fresh peas a bracing pucker. Serve in place of pickles on a sandwich or as an addition to a cheese board.
Combine vinegar, water and salt in a large saucepan. Bring to a boil over medium-high heat. Cook, stirring, until the salt dissolves, about 2 minutes. Remove from heat and add garlic, dill seed, mustard seed and crushed red pepper. Add peas to the brine and let marinate, stirring occasionally, for 15 minutes. Drain. Toss the peas with dill.