In a large skillet, heat olive oil over medium heat. Add onion and garlic and cook until tender. Remove from skillet and set aside.: You will notice the onion release moisture and go translucent, filling the kitchen with a sweet, savory scent while the minced garlic becomes aromatic without browning. The sizzling sound at medium heat should be steady but not frantic, and the edges of the onion should soften, not char. This stage matters because properly softened aromatics form the flavor foundation for the entire soup. If the garlic browns, it can taste bitter, so keep the heat moderate and stir frequently. When they are tender, transfer them to a plate to prevent overcooking while you prepare the roux.
Add butter to skillet and cook until melted. Add in flour and whisk until well combined. Add in softened cream cheese and spices and stir until combined.: As the butter melts it should foam slightly and smell nutty, creating an even coating across the pan. Stir in the flour to form a paste, whisking to remove lumps, and watch the mixture shift to a pale, sandy texture which indicates the raw flour taste is cooking out. When you fold in the softened cream cheese , it should melt into a glossy, cohesive base. Add the kosher salt , black pepper , and thyme so their aromas bloom in the warm fat. This technique ensures a smooth, stable thickener; rushing it or adding liquid too soon will produce clumps, so proceed only once the roux looks even and fragrant.
Pour chicken broth into skillet and whisk ingredients until are smooth. Add in milk and whisk again until smooth. Bring to a gentle simmer and continue whisking to avoid lumps. Add in heavy cream, and whisk until smooth.: When you pour the warm chicken broth slowly into the roux and whisk continuously, the mixture should loosen into a silky sauce with no visible streaks of flour. Adding the milk in stages keeps the texture uniform, and as the pot comes to a gentle simmer you will see small bubbles around the edges and smell an inviting, combined savory and dairy aroma. Keep whisking so the sauce does not cling or scorch, which would give a cooked milk taste. Finally, the heavy whipping cream rounds the body into a lush, velvety finish. If the pot boils vigorously, reduce the heat to avoid separating the dairy.
Add in veggies, potatoes, and/or chicken and stir to fully combine ingredients. Cook on a low simmer for approximately five minutes stirring regularly.: When you fold in the thawed mixed vegetables , pre cooked diced chicken , and potatoes, the pot will cool slightly and then come back up to a gentle simmer, releasing a chorus of soft bubbling sounds. Stirring helps distribute heat so each piece gets warmed through and coated in the creamy base. The visual cue is tender vegetables and warm, plump chunks of chicken suspended in a glossy broth. Simmering briefly preserves the texture of the veggies so they remain distinct rather than turning mushy. A common mistake is over simmering, which breaks down potatoes, so monitor the five minute window closely.
Give the soup a taste to check and see if more seasoning is needed, and if so add salt, pepper and seasoning of choice accordingly.: Tasting now lets you balance the dish, because the flavors have melded and you can assess if it needs more kosher salt , a crack of black pepper , or extra thyme . Pay attention to the temperature as well, because cold food can taste less seasoned. I always add seasoning gradually to avoid over salting. If you add too much salt, dilute with a bit more milk or chicken broth .
Serve immediately.: The finished soup should be steaming and fragrant, with a creamy sheen and tender bites of vegetables and chicken . Serve while hot so the texture stays silky and the flavors feel vibrant. If you let it sit too long, the consistency thickens; you can always loosen it with a splash of milk when reheating. Enjoy right away for the best contrast between the warm broth and the soft veggies.