PREP: Preheat the oven to 400 degrees F. Line a very large sheet pan (15x21-inches) with parchment paper for easier clean-up (optional).
POTATOES AND CARROTS: Halve the baby red potatoes (or cube if they are larger). If not using baby potatoes, the potato pieces should be cut to ~1-inch pieces. In a small bowl, mix together all of the seasonings: the dried basil, thyme, oregano, paprika, onion powder, and salt and pepper (I use a heaping ¼ teaspoon of salt and pepper). Mix together.
BAKE: Place the halved red potatoes and baby carrots on the sheet pan. Pour 2 tablespoons of olive oil and half of the seasoning mix on top. Toss to combine and place in the oven for 20 minutes.
ASPARAGUS, ONION, AND SAUSAGE: Meanwhile, prepare the asparagus by snapping off the ends and cutting into 2-inch pieces. Measure to get 2 cups asparagus. Thinly slice ½ of a yellow onion (¼-inch thick slices). Cut the sausage into ½-inch thick coins.
ADD TO SHEET PAN: Remove the potatoes and carrots from the oven and using a spatula, push them to one side of the pan. On the other side, add in the chopped asparagus, sliced onion, sausage, and minced garlic. Add the remaining 2 tablespoons olive oil and remaining seasoning mix. Toss to combine and then toss everything together with the potatoes and carrots. Make sure to space out veggies/sausage; if the ingredients are overlapping, the bake time will be longer and the veggies will steam instead of roast.
BAKE AGAIN: Bake for another 10-15 minutes or until veggies are roasted to your desired preference. Top the dish with freshly grated Parmesan and fresh parsley as desired. Enjoy immediately.
