1. Heat oven to 425 degrees with a rack in middle position. Cook barley in a medium pot of boiling salted water, stirring occasionally, until tender, 20 to 30 minutes. Drain and set aside to cool.
2. Meanwhile, toss sweet potatoes with 3 tablespoons oil on a baking sheet and season with salt and pepper. Roast until charred and tender, 20 to 30 minutes, stirring halfway through. Let cool briefly.
3. Zest and juice one grapefruit into a large bowl (remove any seeds). Whisk in remaining 1/3 cup oil, the honey, red pepper flakes (if using), and 1/4 teaspoon salt. Transfer half of dressing to a small bowl and set aside for serving. Slice peel and pith from remaining grapefruit, then cut grapefruit into wedges or half-moons; transfer to a separate bowl along with any juice.
4. When barley and sweet potatoes have cooled somewhat, add to bowl with dressing along with half of sliced grapefruit, half of feta, and half of parsley. Toss gently to coat and season with salt and pepper to taste. Transfer to a serving dish, then top with remaining grapefruit, feta, and parsley and sprinkle with sunflower seeds (if using). Serve warm or at room temperature with remaining dressing on the side.
Source: Hannaford fresh Magazine, December 2022