Step 1

Preheat the oven to 425 F with a rack in the center position. Line a colander with a clean tea towel.

Step 2

In a large pot or Dutch oven, heat 1 tablespoon oil over medium-high. Add onions, 1/8 teaspoon salt and 1/8 teaspoon pepper. Cook until onions have softened, 4 to 5 minutes. Add collard greens, spinach, scallions, garlic and 1/4 cup of water. Season with 1/4 teaspoon salt and a few grinds of pepper. Reduce heat to medium, cover and cook until greens are tender, about 5 minutes. Season to taste with salt and pepper. Transfer the greens to the prepared colander. Cool slightly, about 10 minutes. Gather up the ends of the towel, then squeeze as much moisture out of the greens as possible. Transfer greens to a large bowl.

Step 3

In the same bowl, add the quinoa, parsley, mozzarella, 1 cup crumbled feta, dill, 3/4 teaspoon of salt and 1/4 teaspoon of pepper. Stir to combine.

Step 4

Arrange the pepper halves, cut side up, in a large, ovenproof skillet. Drizzle with olive oil, then season with salt and pepper. Divide the filling among the peppers (about 1 cup filling per pepper half). Lightly drizzle the peppers with olive oil, then pour 3 tablespoons of water in the bottom of the skillet. Cover the skillet tightly with foil.

Step 5

Bake for 40 to 45 minutes until the peppers are tender, the cheese has melted and the filling is warm. Remove from the oven and let stand for 5 minutes.

Step 6

Meanwhile, finely zest and juice half of a lemon. Cut remaining lemon half into wedges. In a small bowl, combine the lemon zest and juice, Greek yogurt, 3 tablespoons water, remaining 1 tablespoon olive oil, 1/2 teaspoon salt and pepper. Whisk until smooth.

Step 7

Transfer the peppers to a serving platter. Drizzle with lemony yogurt and sprinkle with remaining dill and feta. Pass lemon wedges at the table.