Position rack in middle of oven. Preheat oven to 375°F/190°C. Coat the inside of a 1 1/2 quart to 2-quart (1.4 L to 2 L) casserole dish with nonstick spray; set aside.

Bring a large pot of salted water to a boil. Meanwhile chop off and remove the very ends of the Swiss chard. Finely chop the remaining stalks and leaves. Add all of the Swiss chard and the spinach to the boiling water and boil for a minute or two, stirring all the greens into the water to get well saturated, cooking until wilted. Drain in colander in sink and allow to cool.

Meanwhile, add oil to a large sauté pan over low-medium heat and heat till shimmering; add leeks, scallions and red bell pepper and sauté for a couple of minutes until softened. Season with thyme and liberally with salt and pepper.

Going back to colander in sink, use the back of a sturdy spoon to squeeze water out of the greens, then use your hands if necessary to squeeze as much water out of them as possible. You can wrap them up in a clean tea towel and literally wring them out over the sink. Add to sauté pan, stirring everything together well. Taste and adjust seasoning. Cool briefly.

Whisk eggs in a large bowl, whisk in cheese, then add cooled veggie mixture and cooked quinoa and fold everything together well. Scrape into the prepared dish and bake for about 20 to 25 minutes or until eggs are just set and the mixture is a little puffed.