@Vann see, i mix up the oil, vinegar, and spices into a savory salad dressing beforehand and leave that on the counter.

0) preheat oven to 420
1) dump pre-cut veggies on the, by now, "well seasoned" cookie sheet
2) squirt salad dressing on veggies
3) stir
4) place in the oven, no matter if preheating is finished
5) check on it in 30 or 40 minutes