Whisk together the olive oil, Dijon, vinegar, smoked paprika, coriander, cumin, thyme, salt, and pepper.
4 Toss the vegetables thoroughly with the seasoning mixture.
5 Carefully spread them over the hot sheet pans in a single layer. Avoid crowding them or they will steam.
6 Roast for 25–35 minutes, turning after approximately 18 minutes, until browned at the edges and tender inside.
7 Toss with the lemon juice and parsley just before serving. Add pumpkin seeds or pecans for crunch, if desired.