Bacon serves as the base for this quick-cooking ragu that calls for a rotisserie chicken and fragrant fennel and thyme.
Bring a large pot of water to a boil for the pasta.
Pull the meat from the chicken (reserve the skin and bones for stock). Using your fingers or 2 forks, finely shred the meat.
In a large skillet, heat the oil, three turns of the pan, over medium-high. Add the bacon and cook, stirring occasionally, until the fat begins to render, 2 to 3 minutes. Add the onion, fennel bulb, thyme, and garlic; season with salt and pepper. Cook, stirring occasionally, until the vegetables soften, about 10 minutes. Add the chicken and cook, stirring often, until heated through, about 2 minutes. Add the wine and cook, stirring often, until absorbed, about 1 minute. Add the chicken stock and milk. Simmer the sauce, stirring often, until reduced slightly, 2 to 3 minutes.
Meanwhile, salt the boiling water. Add the pasta, and cook to 1 minute less than package directions. Reserve 1 cup of the starchy cooking water. Drain the pasta.
Add the pasta, cooking water, and cheese to the sauce; season. Toss until coated, 1 to 2 minutes. Serve in shallow bowls. Top with the dill and fennel fronds.