Slice the zucchini: Trim the ends and cut into 1/4-inch half-moons. Pat dry with a paper towel to reduce extra moisture.
Heat the pan: Place a large skillet over medium heat.
Add butter and olive oil. When the butter melts and foams, you’re ready to cook.
Sauté the zucchini: Add zucchini in an even layer. Don’t overcrowd the pan.
Cook 3–4 minutes, stirring once or twice, until edges start to brown.
Season and add garlic: Sprinkle with salt, pepper, red pepper flakes, and Italian seasoning. Add minced garlic and cook 30–45 seconds, stirring, until fragrant. Avoid burning the garlic.
Make it creamy: Pour in the heavy cream.
Reduce heat to medium-low. Stir in Parmesan and cream cheese (if using) until melted and the sauce thickens, 2–3 minutes.
Adjust the balance: If the sauce is too thick, splash in a tablespoon of water or cream. If it’s too thin, simmer another minute.
Add lemon juice or zest if you like a little brightness.
Taste and finish: Taste for salt and pepper. Remove from heat. Garnish with chopped parsley or basil and extra Parmesan.
Serve hot: Enjoy as a side with grilled chicken, steak, or salmon, or serve it as a light main with a simple green salad.