In a large pot, heat the olive oil over medium heat. Add the chopped onion and sauté until it becomes translucent. This usually takes about 5 minutes. The smell of onions sizzling in olive oil is a great way to kickstart your cooking adventure.

Add the spicy Italian sausage to the pot. Use a wooden spoon to break it apart as it cooks. You want it to brown evenly. This should take around 6-8 minutes. Don’t rush this step; the sausage caramelizing will deepen the flavor significantly.

Once the sausage is browned, introduce the minced garlic, oregano, basil, and red pepper flakes (if using). Stir everything together and cook for another minute. This is where the magic happens; your kitchen will start to smell amazing.

Next, add the chicken broth to the pot. Scrape the bottom of the pot with your wooden spoon to mix any browned bits. Those bits are flavor nuggets that you don't want to waste!

Toss in the diced red-skinned potatoes and the bay leaf. Allow the mixture to come to a gentle boil, then reduce the heat and simmer for around 15 minutes. You want the potatoes to be fork-tender.

Once the potatoes are cooked, stir in the baby spinach. Cook for a couple of minutes until the spinach wilts. Finally, swirl in the heavy cream and sprinkle the smoked paprika. Mix until it's all well combined and the soup has a creamy consistency.

Taste your soup and season it with kosher salt and cracked black pepper. Discard the bay leaf before serving. Ladle the soup into bowls and sprinkle each with a bit of grated Parmesan cheese.