About 1-2 hours before beginning the cooking, remove the chicken from the fridge, drain any liquid off and dry it off. Sprinkle the chicken heavily with kosher salt, being sure to get the back and sides of the chicken thighs, and leave out to come to room temperature. The salt will remove moisture from the chicken, which will help create a crispy skin.
In a shallow bowl, add the spice blend mixture and whisk until well combined. Set small bowl aside.
Begin by patting the chicken dry with paper towels. Season both sides with a pinch of kosher salt and black pepper. Season skin side with pinches of the spice blend. There should be about ½ teaspoon left in the spice blend bowl after seasoning the chicken.
In a large pot or large skillet with high sides, heat olive oil over medium-high heat. Add all four seasoned chicken thighs skin-side down. Sear the chicken skin. Cook for about 5 minutes, until crispy.
While the chicken is skin side down in the pot, sprinkle the other side with salt and pepper.
Flip the chicken after 5 minutes (or until skin is golden brown) and cook most of the way through (until about 90% cooked). Set chicken aside skin side up on a paper towel-lined plate or paper towel-lined tray.
In the same pot, add 1 tablespoon butter. Melt.
Add the white parts of the green onion, stir to saute until soft. Add orzo and lightly toast until golden, then add broth and stir. Bring to a boil. Simmer until orzo is cooked through.
Add the remaining seasoning mix (about ½ teaspoon) and ¼ - ½ cup sour cream, depending on your preference. Taste & add more seasoning as needed.
Add chicken thighs back to the pot on top of the orzo, skin side up. Continue to simmer until all the broth is absorbed and chicken is cooked through to about 160-165°F
Divide portions and serve in a medium bowl. Garnish with remaining green onions and/or fresh chives.