Prep the chicken: Pat the chicken dry with paper towels. Toss with 1/2 teaspoon salt, black pepper, and smoked paprika if using.
Dry chicken browns better and stays juicier.
Blanch or steam the broccoli (optional but recommended): Bring a small pot of salted water to a boil. Cook broccoli for 1 minute, then drain and rinse with cold water to keep it bright. This helps it cook quickly in the skillet without going mushy.
If you prefer, skip this step and cook the broccoli longer in the pan later.
Heat the pan: Set a large skillet over medium-high heat. Add olive oil and 1 tablespoon butter. When hot and foamy, add the chicken in a single layer.
Don’t crowd the pan; cook in two batches if needed.
Sear the chicken: Cook 4–6 minutes, stirring occasionally, until the pieces are lightly browned and cooked through. Remove to a plate and tent loosely with foil. This keeps it from overcooking while you make the sauce.
Sauté the broccoli: Reduce heat to medium.
Add another 1 tablespoon butter to the skillet. Add broccoli and a pinch of salt. Sauté 2–3 minutes until crisp-tender and slightly charred in spots.
Build the garlic butter base: Push the broccoli to the edges of the pan.
Add the remaining 1 tablespoon butter to the center along with the minced garlic and red pepper flakes. Stir 30 seconds, just until fragrant. Don’t let the garlic brown.
Deglaze and simmer: Pour in the chicken broth and lemon juice.
Scrape up any browned bits from the bottom—they’re flavor gold. Simmer 1–2 minutes to let the sauce reduce slightly.
Return the chicken: Add the chicken and its juices back to the skillet. Toss everything together until the chicken is coated and warmed through, about 1–2 minutes.
Taste and adjust seasoning with more salt, pepper, or lemon.
Finish and serve: Sprinkle with parsley. For a richer finish, add Parmesan and lemon zest. Serve hot as is, or spoon over rice, cauliflower rice, or buttered noodles.