Bring chicken broth to a boil in a medium saucepan, covered. Add saffron and reduce to a bare simmer, covered.
Melt butter over medium heat in a heavy-bottomed 8-qt. pot. Add onion; cook until translucent and turning golden, 10 minutes. Stir in thyme. Add rice and cook, stirring constantly, until edges of grains look translucent, about 2 minutes.
Add wine and salt to rice and cook, stirring, until wine is completely absorbed. Add about 1 cup hot broth and simmer, stirring, until absorbed; reduce heat to medium-low if mixture starts to boil. Keep adding broth, a ladleful at a time, stirring until each addition is absorbed before adding the next, until rice is just tender to the bite and still slightly soupy, 15 to 30 minutes. You may have broth left over.
Remove rice from heat and stir in cheese, crème fraîche, 2 tbsp. chives, the preserved lemon, and Marash pepper. Serve immediately with Spice-Crusted Scallops. Scatter more chives on top.
*Mildly hot, fruity Marash and Aleppo peppers are available at some Middle Eastern markets and by mail order from avantisavoia.com
Note: Nutritional analysis is per serving.