Pour the olive oil into a large bowl. Add the lemon juice, preserved lemon, garlic, mint, honey, both mustards, and half of the salt. Whisk to combine. Place the chicken thighs in the bowl and toss to coat. Cover and chill for at least an hour.
While the chicken is marinating, place the saffron in a mortar and pestle along with a pinch of salt. Grind until a fine powder forms. Transfer the powder to a small bowl and cover with boiling water (roughly 2 tbsps and no more than a 1/4 cup). Set aside to steep.
Once the hour has passed, preheat the oven to 400°F. In a large cast-iron skillet, heat a quarter-sized amount of olive oil over medium-high heat until nearly smoking.
Take the chicken thighs out of the marinade and place them in the skillet, fat-sized-down. Reserve the marinade. Sear the chicken on both sides until just golden. We're not trying to cook the chicken, we just want to render some of the fat out and get some color on the thighs. Once golden, transfer the thighs to a plate and set aside.
Reduce the heat to medium-low and add the shallots along with a pinch of salt. Saute until just softened, about five minutes. Add the farro and saute until it turns a slightly darker shade and gives off a nutty aroma.
Pour the stock into the skillet and add the reserved marinade, the remaining salt, the saffron and its steeping liquid, and the green olives. Stir to combine. Increase the heat and bring the mixture to a boil. Let cook for 2-3 minutes before adding the chicken thighs back into the skillet. Transfer the skillet to the oven and bake for 25-30 minutes, rotating once halfway.
Once the farro is tender and most of the liquid has been absorbed, take the skillet out of the oven and let stand for 10 minutes before serving. Garnish with fresh parsley, sunflower micro-greens, and fresh lemon wedges.