Preheat oven to 400 degrees F. Toss the citrus segments with olive oil and salt, then lay on a parchment covered baking sheet and roast for 5 minutes, then broil for 2 minutes.
Meanwhile, stir together mascarpone, cardamom, and as much honey as you'd like depending how sweet you like things. Start out with 1 tablespoon and go from there.
Remove citrus from oven, let cool for 5 minutes, then divide between four bowls with the mascarpone. Top with crushed pistachios.
Notes
You can roast the fruit two days ahead of time, as well as the mascarpone. Just keep them separate, then assemble when ready to serve.