Heat the olive oil in a large pot over medium heat.
Add the sliced smoked sausage and cook for 5-7 minutes until browned. Remove the sausage with a slotted spoon and set aside.
In the same pot, add the diced onion and cook for 4-5 minutes until softened.
Add the minced garlic and cook for 1 minute until fragrant.
Sprinkle the flour over the onions and garlic, stirring constantly for 2 minutes to form a roux.
Gradually whisk in the chicken broth, ensuring no lumps form.
Add the diced potatoes, dried thyme, smoked paprika, salt, and pepper.
Bring the mixture to a boil, then reduce heat to a simmer and cook for 15-20 minutes until the potatoes are tender.
Stir in the whole milk and heavy cream.
Return the browned sausage to the pot and cook for an additional 5 minutes to heat through.
Add the unsalted butter and stir until melted and incorporated.
Taste and adjust seasoning with additional salt and pepper if needed.
Remove from heat and stir in the chopped fresh parsley.
Ladle the chowder into bowls and serve hot.