Prep the produce: Slice the mushrooms, dice the onion, and mince the garlic. Have the cream cheese cut into small cubes so it melts quickly.
Brown the turkey: Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add the ground turkey, season with salt and pepper, and cook, breaking it up, until lightly browned and cooked through, about 5–7 minutes.
Transfer to a plate and keep warm.
Sauté the mushrooms: In the same skillet, add 1 tablespoon butter. Add mushrooms with a pinch of salt. Cook undisturbed for 2 minutes, then stir and cook until they release their moisture and turn golden, 5–6 minutes.
Remove and set aside with the turkey.
Soften the aromatics: Reduce heat to medium. Add the remaining 1 tablespoon butter and the diced onion. Cook until translucent, 3–4 minutes.
Stir in the garlic and cook 30 seconds, just until fragrant.
Build the sauce base: Stir in smoked paprika, thyme, and red pepper flakes if using. Add the Dijon. Pour in the broth, scraping up the browned bits from the bottom of the skillet for extra flavor.
Simmer 2 minutes.
Make it creamy: Lower heat to medium-low. Add the heavy cream and cream cheese. Whisk or stir until the cream cheese melts and the sauce is smooth and slightly thickened, 3–4 minutes.
Taste and season with salt and pepper.
Combine and finish: Return the turkey and mushrooms (plus any juices) to the skillet. Stir to coat in the sauce and simmer 2–3 minutes. Add lemon juice and a handful of chopped parsley.
Adjust seasoning as needed.
Serve: Spoon over cauliflower rice, swirl through zucchini noodles, or serve alongside sautéed spinach. Garnish with extra parsley and a grind of black pepper.