Preheat the oven to 450 degrees F. Heat the olive oil in a large ovenproof skillet over medium heat. Add the saffron, coriander, garlic, shallot and 1 teaspoon salt and cook, stirring, until the shallot is translucent and the oil turns yellow, about 5 minutes. Add the cauliflower, lemon juice and 1/3 cup water. Increase the heat to medium high and cook, stirring occasionally, until the cauliflower turns yellow and the water has mostly evaporated, about 5 minutes.
Transfer the skillet to the oven. Roast, stirring halfway through, until the cauliflower is tender and golden, about 15 minutes. Season with salt and sprinkle with parsley.