In a large pot, heat the stove to medium-high and add the Italian sausage. Cook for 7-10 minutes, breaking it apart as it browns until it's nicely caramelized and no longer pink. Transfer the sausage to a paper towel-lined plate to drain excess grease.

In the same pot, lower the heat to medium and add diced onion and celery. Sauté for 4-5 minutes until the vegetables soften and the onion turns translucent.

Sprinkle in the flour and minced garlic, stirring well to combine. Cook for another minute until fragrant.

Gradually pour in the chicken broth, continuously stirring to dissolve the flour mixture. Bring to a gentle boil while scraping up any browned bits from the bottom of the pot.

Once boiling, add the diced tomatoes and dried oregano. Return the browned sausage to the pot and allow the mixture to simmer.

Stir in the heavy cream and uncooked orzo, then reduce the heat to a low simmer. Cook for about 12 minutes until the orzo is tender.

Fold in the fresh baby spinach, allowing it to wilt. Taste and season with salt and pepper according to your preference.