Sauté Aromatics into a Butter-Flour Roux: In a large soup pot, melt butter over medium-high heat. Add onions, celery, garlic, mustard powder, smoked paprika, salt and pepper. Cook covered until onions turn translucent, around 5-7 minutes. Add flour and stir until it turns pasty, around 1 minute.
Build the Broth: Add turkey and chicken broth, bring the pot to a boil over high heat, then reduce the heat to low and simmer covered for 10-15 minutes, until turkey becomes tender and flavors meld.
Add Dairy: Increase heat to medium-low and add cream cheese and cheddar cheese and whisk until cheese is fully melted, around 4-5 minutes. Remove pot from heat and let cool for 10-15 minutes, add heavy cream and stir.
Cook Pasta and Combine: In a separate small pot, bring 8 cups of water to a boil over high heat. Add macaroni, reduce heat to medium-high, and simmer uncovered, stirring occasionally, for 8-11 minutes, or until al dente. Pour the pasta into a strainer in the sink. Once strained, you have the option to add the pasta when serving for a thinner broth, or you can go ahead and add pasta now for a thicker broth.
