In a small bowl combine sliced shallots, vinegar and salt. Toss to coat. Submerge shallot slices so they are covered with as much vinegar as possible. Cover and let stand at room temperature for 1 hour or chill up to 2 days ahead. Drain shallots; reserve vinegar mixture for dressing and pickled shallots for salad.

To assemble, arrange chard on a serving platter. Top with shredded beet, salmon, pickled shallots (drained from step 1), strawberries and pistachios.

For the dressing, in a small bowl whisk together 3 tablespoons of the drained vinegar mixture, Dijon mustard, rosemary and salt. Slowly pour oil into vinegar mixture, whisking constantly, until dressing is well combined. Drizzle dressing over salad to serve.