Place the chicken sausage in a large pot or deep skillet over medium-high heat. Cook for about 5 minutes, breaking it into bite-sized pieces with a wooden spoon as it cooks, until it's browned and cooked through. This initial browning develops flavor that will carry through the entire dish. Once the sausage is cooked, add the diced onion and cook for another 3-4 minutes, stirring occasionally, until the onion begins to soften and become translucent.

Stir in the minced garlic and cook for about 30 seconds until fragrant, being careful not to let it burn. Add the frozen corn and cook for 2-3 minutes, stirring occasionally. I like to add the corn at this point rather than earlier so it stays bright and doesn't overcook into mushiness by the end of the cooking time.

Pour in the orzo and chicken broth, stirring to combine everything evenly. Bring the mixture to a boil over medium-high heat, then immediately reduce the heat to medium-low and simmer gently for about 10 minutes, stirring occasionally. The orzo will absorb the broth as it cooks and becomes tender—this is the heart of the dish where all the flavors meld together.

Stir in the packed spinach, crushed red pepper flakes, and black pepper to taste. Cover the pot and let it sit for 2 minutes off the heat, which allows the spinach to wilt gently from the residual heat without becoming mushy. I prefer this gentle approach over cooking the spinach directly in the hot broth, as it keeps the spinach fresher and more vibrant.

Give the dish a gentle stir, then divide among bowls or plates. Top each portion with freshly grated Parmesan cheese and an extra grind of black pepper if desired. Serve immediately while the dish is hot and the flavors are at their peak.