Combine the spice rub. Coat the leg quarters all over and rest uncovered in the fridge at least 1 hour, ideally overnight.
Heat the oven to 350°F. Heat the olive oil in a large Dutch oven or braiser over medium-high. Sear the chicken skin-side down until deeply browned, 7 to 8 minutes. Flip and sear 2 minutes more. Remove to a plate.
Pour off all but 2 tbsp of fat. Add the onion and cook until softened and caramelized, 8 to 10 minutes. Add the garlic and cook 30 seconds.
Add the apricots and cook 2 minutes, until they blister and take on a little color.
Deglaze with the orange juice, scraping up the fond. Add the chicken stock, orange zest, and potatoes, and bring to a simmer.
Nestle the chicken back in skin-side up. The liquid should come partway up the legs with the skin sitting above the surface.
Transfer uncovered to the oven and cook 45 to 50 minutes, until the potatoes are tender and the chicken pulls easily from the bone.
If the braising liquid is still thin, simmer on the stove until thickened.
Scatter over the pistachios and parsley, add a drizzle of date syrup if you like, and serve straight from the pan.
