In bowl, toss a few handfuls of arugula (per serving) with a drizzle of olive oil and a pinch of salt. Add a few forkfuls of pickled fennel (let most of the brine drip off) and toss once more.
Arrange orange supremes, sliced avocado, and pieces of gravlax over the top of the salad. I'd figure on half an orange, half an avocado, and about 2 oz. of gravlax per serving. Scatter a few pistachios over the top and serve.
Recipe by strawberryplum at http://www.strawberryplum.com/arugula-salad-with-gravlax-avocado-pickled-fennel/