Heat 1 tbsp olive oil and the butter in a large dutch oven or large deep skillet over medium heat. Add the sliced onions and cook for 6-7 minutes, stirring occasionally, until softened. Add a splash of water, cover, and continue cooking for another 20–30 minutes over medium-low heat, stirring occasionally and adding a splash of water whenever the onions begin sticking to the pan. Continue cooking until the onions are caramelized to your desired color. Remove the onions and set aside.

Add a little more oil to the pan. Add the sausage pieces and cook for 4-5 minutes, until browned and cooked through. Remove and set aside.

Return the caramelized onions to the pan. Add the orzo and beef stock, stirring to prevent orzo from sticking to the bottom of the pan. Stir in the thyme, roasted garlic seasoning, beef bouillon, Worcestershire sauce, salt, and black pepper. Bring to a gentle simmer and cook for about 8-9 minutes over low heat, stirring occasionally.

Stir in the spinach, heavy cream, cooked sausages, and grated Parmesan. Continue cooking for 1–2 minutes, stirring until the spinach wilts and everything is well combined and creamy.

Sprinkle the shredded gruyere evenly over the top. Cover the pan with a lid and turn off the heat. Let it sit about 2 minutes until the Gruyère is completely melted.

Serve warm and enjoy!