Wash and prepare all produce.
Heat a large sauté pan or deep skillet over medium heat with a light drizzle of olive oil. Add the chicken and cook until lightly golden and cooked through. Remove from the pan and set aside.
Add 1 tablespoon olive oil to the same pan. Add the sliced fennel and cook for about 10 minutes, stirring occasionally, until softened and lightly caramelized on the edges.
Add the leeks and garlic and cook for another 4–5 minutes until the leeks are tender and translucent.
Stir in the sun-dried tomatoes, butter beans, thyme, and parsley. Cook for 2–3 minutes to build flavor.
Pour in the white wine and let it bubble for 2–3 minutes to reduce slightly.
Add the chicken broth, red chili flakes, spinach, cooked chicken, salt, and pepper. Bring to a gentle simmer and cook until the broth reduces by about half, around 8–10 minutes.
Remove the skillet from the heat. Stir in the butter, mascarpone, and lemon juice until smooth and creamy.
Taste and adjust seasoning as needed before serving.