Peel the squash, seed it, and cut it in 3/4-inch cubes. The best method to do this is to cut the squash in half with your biggest, sharpest knife, and scoop out the seeds. Then lay the halves cut side down and slice them in wide strips. Lay the strips on their sides and cut off the thick, hard rind in pieces, then cube the orange flesh. This method allows you to keep the cutting edge of your knife always safely aimed down toward the board, very important when applying pressure to a tough hide.

Cut the green tomatoes in 1-inch chuncks. Peel the red onions and cut them in thin wedges. Scrub the potatoes and cut them in pieces no larger than the squash pieces. Peel the garlic cloves and slice the larger ones in half lengthwise.

Toss all the vegetables together with the olive oil and salt until they are evenly coated, spread them on two baking sheets, and roast them at 400 degrees for about 1 1/4 to 1 1/2 hours. Stir and turn the vegetables a couple times in the course of the cooking time. They should be perfectly tender, with crisped, browned edges here and there.

Serve the vegetables with Couscous with Moroccan Spices.