With the rack in the middle position, preheat the oven’s broiler. Line a baking sheet with aluminum foil.
In a saucepan of salted boiling water, cook the quinoa for 12 to 15 minutes or until tender. Drain and rinse under cold running water. Let cool.
In a large bowl, combine the cucumbers, vinegar, mirin and sambal oelek. Let marinate for 10 minutes.
On the prepared sheet, toss the onions with the oil. Roast for 5 minutes or until tender. Add the zucchini. Season with salt and pepper and toss well. Continue roasting for 5 to 8 minutes or until the zucchini begin to brown.
Add the quinoa and roasted vegetables to the cucumbers. Adjust the seasoning. Garnish with the cilantro. Delicious with maple-glazed pork chops (see recipe).