Bring a large pot of salted water to a boil and cook pasta according to package directions until al dente. Reserve ½ cup pasta water, then drain and set pasta aside.

While pasta cooks, season the chicken bites with salt, pepper and garlic powder. Lightly toss with the 2 tbsp flour if you want a slight crust (optional).

Heat 1 tbsp olive oil and 2 tbsp butter in a large skillet over medium-high heat. When hot, add chicken in a single layer. Sear chicken 3–4 minutes per side until golden and cooked through. Transfer chicken to a plate.

Reduce heat to medium. Add remaining 1 tbsp olive oil and 2 tbsp butter to the skillet. Sauté the shallot (or onion) for 1–2 minutes until softened, then add the minced garlic and cook for 30–45 seconds until fragrant.

Pour in the chicken broth to deglaze the pan, scraping up browned bits. Simmer for 1–2 minutes to concentrate flavor.

Stir in the heavy cream and bring to a gentle simmer. Let the sauce cook for 3–5 minutes until slightly thickened. If it gets too thick, whisk in reserved pasta water a splash at a time.

Lower heat and add grated Parmesan, stirring until melted and smooth. Add lemon juice (if using) and season with salt, pepper, and red pepper flakes to taste.

Return chicken bites to the skillet and toss to coat in the sauce. Cook for 1–2 minutes to heat through.

Add drained pasta to the skillet, tossing to coat everything in the creamy Parmesan sauce. If needed, thin with reserved pasta water to reach your desired consistency.

Garnish with chopped parsley or basil and an extra sprinkle of Parmesan. Serve immediately.