Prep. Preheat oven to 400 degrees F.
Trim the asparagus. Rinse the asparagus and trim the tips. I like to place a bunch of spears on a cutting board and slice the woody dry ends off. You don't have to cut a lot, just most of the thicker tougher white part.
Add seasonings. Place asparagus stalks on a sheet pan (lined with foil or parchment paper) or baking dish in a single layer, and drizzle with 1 ½ tablespoons (or more as needed) olive oil, season with salt, black pepper, onion, and garlic powder.
Toss to combine with hands or kitchen tongs (or use a plastic zip-top bag for even distribution of seasonings).
Tomatoes (optional add-in): In a medium bowl, toss tomatoes with the remaining olive oil, and salt pepper.
Assemble. Arrange the asparagus on one side and the other side with the tomatoes. Sprinkle both or just the asparagus with parmesan on top.
Cooking time. Bake in preheated oven for 10-15 minutes. You’ll know when asparagus is done when its color becomes darker green and the cheese is melted. Tomatoes will start to brown lightly.
Ready to serve. Serve the cheesy asparagus immediately garnished with fresh basil leaves, lemon juice, sea salt flakes and balsamic glaze (optional!).