Preheat the oven to 400°F (200°C).

In a large mixing bowl, combine the trimmed asparagus, sliced zucchini, and yellow squash.

In a small bowl, whisk together olive oil, minced garlic, salt, black pepper, and optional red pepper flakes.

Drizzle the olive oil mixture over the vegetable blend and toss gently to coat.

Spread the coated vegetables in a single layer on a baking sheet.

Roast the vegetables in the oven for 15-20 minutes until tender and golden.

Remove from the oven and drizzle with fresh lemon juice and sprinkle with lemon zest.

Gently toss the vegetables to distribute lemon flavors evenly.

Transfer to a serving dish and top with freshly grated Parmesan cheese.

Garnish with chopped parsley just before serving.