Bring a large pot of salted water to a boil. Add the spaghetti noodles and cook according to package directions until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium heat. Add the diced onion and sauté for about 3-5 minutes until translucent. Stir in the minced garlic and cook for an additional minute until fragrant.
Increase the heat to medium-high and add the lean ground beef to the skillet. Cook, breaking it apart with a spatula, until browned and cooked through, about 5-7 minutes.
Sprinkle the taco seasoning over the cooked beef, stirring to combine. Pour in the can of Rotel tomatoes, beef broth, and tomato paste. Stir well to mix all the ingredients thoroughly.
Reduce the heat to low and add the softened cream cheese to the skillet. Stir until the cream cheese is fully melted and incorporated into the sauce.
Add the cooked spaghetti noodles to the skillet, tossing to coat the pasta evenly with the taco sauce. Let everything heat through for about 2-3 minutes.
Remove the skillet from heat and sprinkle the shredded Colby Jack cheese over the top. Allow it to melt slightly before serving. Garnish with chopped fresh cilantro for a pop of color and flavor.
