Cook the pasta: Bring a large pot of salted water to a boil. Add the pasta and cook until just al dente. Reserve about 1/2 cup of pasta water, then drain and set aside.
Sauté the aromatics: In a large skillet, heat olive oil over medium heat.
Add the diced onion and cook until softened, about 3–4 minutes. Stir in the garlic and cook 30 seconds, until fragrant.
Brown the protein: Add the ground beef or turkey to the skillet. Cook, breaking it up with a spoon, until no longer pink.
If there’s excess fat, drain it off.
Season and simmer: Sprinkle in the taco seasoning. Stir to coat. Add the tomatoes with green chiles and the broth.
Let it simmer for 3–4 minutes to meld the flavors.
Make it creamy: Lower the heat. Add the cream cheese and stir until fully melted and smooth. Whisk in the sour cream, milk, and ranch seasoning until the sauce is silky.
Add the extras: Stir in corn, black beans, or bell pepper if using.
Simmer 2–3 minutes to warm through. Taste and season with salt and pepper as needed.
Toss with pasta: Add the drained pasta to the skillet and toss to coat. If the sauce is too thick, splash in reserved pasta water until it reaches your preferred consistency.
Cheesy finish: Sprinkle in the shredded cheese and stir until melted and glossy.
Remove from heat.
Top and serve: Garnish with cilantro, green onions, or jalapeños. Serve with lime wedges for a bright pop.