Preheat the oven to 425F convection or 450F regular bake. Line a baking sheet with parchment paper.
Add the squash to the baking sheet along with the olive oil, thyme, and salt. Use your hands to thoroughly toss to coat. Bake for 25-30 minutes or until it is caramelized on the edges/bottoms. Let cool off for a few minutes.
Meanwhile, boil your eggs (if using or top with a different protein) if you haven’t already, then peel them.
In a large bowl, whisk together the olive oil vinegar, mustard, and salt until combined. Add the radicchio, apple, feta, and walnuts. Add the warm roasted veg and toss well to coat.
Serve topped with chopped or grated egg, black pepper and parsley (if using).