Prep the ingredients. Cut the chicken into bite-size pieces and season with salt and pepper. Chop your vegetables into small, even pieces so they cook quickly and evenly. Mince the garlic and dice the shallot.

Cook the tortellini. Bring a large pot of salted water to a boil. Cook tortellini according to package directions until just al dente. Reserve 1/2 cup pasta water, then drain and set aside.

Sear the chicken. In a large skillet over medium-high heat, add 1 tablespoon olive oil and 1 tablespoon butter. Add the chicken in a single layer and cook until browned and cooked through, 4–6 minutes. Transfer to a plate and keep warm.

Sauté the aromatics. Lower heat to medium. Add the remaining olive oil and butter to the same skillet. Add shallot and cook 1–2 minutes until softened. Stir in garlic and cook 30–60 seconds until fragrant.

Cook the vegetables. Add firmer vegetables first (like carrots, broccoli, or asparagus stems) and cook 2–3 minutes. Then add quicker-cooking vegetables (like zucchini, bell pepper, peas, cherry tomatoes, or asparagus tips). Season with a pinch of salt and pepper. Cook until crisp-tender, about 3–5 minutes total.

Deglaze the pan. Pour in the white wine, scraping up any browned bits. Let it simmer for 1–2 minutes to reduce slightly. If not using wine, use a splash of chicken broth.

Build the sauce. Add chicken broth and bring to a gentle simmer. Stir in heavy cream and a pinch of red pepper flakes if using. Simmer 2–3 minutes until lightly thickened.

Add cheese and lemon. Reduce heat to low. Stir in the Parmesan until it melts smoothly. Add lemon zest and a squeeze of lemon juice. Taste and adjust seasoning with salt and black pepper.

Combine everything. Return the chicken and any juices to the skillet. Add the cooked tortellini and toss gently to coat. If the sauce seems thick, loosen with reserved pasta water a splash at a time until glossy.

Finish with herbs. Stir in chopped parsley or basil. Remove from heat. Serve warm with extra Parmesan and a grind of black pepper.