Preheat the oven to 375°.
Ready a heavy-bottomed roasting pan or enameled Dutch oven.
MAKE A SALAD
Peel the oranges and cut each crosswise into 4 slices (per step by step, below).
In a small bowl, combine the sliced oranges and the onion, season with 1/8 teaspoon salt, toss, and set aside, covered, at room temperature.
CREATE A SEASONED OIL AND A PASTE
In a second small bowl, combine the sugar, the remaining 3/8 teaspoon salt, the cumin, the cinnamon, the coriander, the ginger, and 2 tablespoons oil. Stir to combine. Set aside.
In a third small, microwave-safe bowl, combine 1/4 cup water and the raisins.
Microwave at HIGH for 1 minute or until the raisins are tender (depending on the power of your microwave).
Drain the raisins and mash to a paste with a fork so that it resembles (the thick kind of) barbecue sauce.
SEASON THE CAULIFLOWER
Place the cauliflower on a large plate or cutting board.
Brush evenly with 1 tablespoon of the olive oil, then the raisin paste, and finally the spiced oil.
Now, put the brush aside and get your hands in there. You know you want to.
Spray your roasting pan evenly with cooking spray.
Place the cauliflower in your roasting vessel and roast for anywhere from 45 minutes to 1 hour and 15 minutes, or until tender. (if a skewer can be inserted and removed without struggle, it's tender.)
Baste periodically. Add a touch of water to the bottom of your pan if you find the edges of the cauliflower are caramelizing too rapidly.
Remove the cauliflower from the oven.
Cover the cauliflower with the lid of your Dutch oven (if it's nowhere to be found, use foil) and let rest for 15 minutes before carving.
CARVE AND SERVE
As if to carve a roast, slice the cauliflower into 8 (1/2-inch to 3/4-inch) slabs.
To serve, smear the surface of each of 8 plates with about 1/2 tablespoon of harissa.
Top each with a slab of cauliflower and then garnish with 1 slice of orange and some of the marinated onion.
Serve and revel in the meatless-ness.
Step by Step: Slicing Oranges
1) Slice the stem end and bottom off the oranges. Keep it straight, so you have a safe
2) Follow the contour of the orange, and cut just past the white pith. If you lose some flesh on the first cut, that's normal. Now, follow the "white line"--where the pith hits the orange. See? No flesh lost. (you or the orange.) Nice.
3) Slice the oranges. Relish in their beauty. Sneak a piece.