For an extra layer of flavor, try grilling the squash and green beans instead of roasting them. If you're not vegan, crumbled feta cheese adds a delicious tangy note. Feel free to experiment with other vegetables like zucchini, bell peppers, or eggplant. The salad can be made ahead of time and stored in the refrigerator for up to 3 days. The flavors will meld together beautifully.