Heat olive oil in a large deep pan (or pot) over medium-high heat and add ground beef. Cook until browned being sure to break up the meat as it cooks. Drain any excess fat.
Add the taco seasoning, diced bell pepper, and Rotel tomatoes with juices to the pan. Stir to combine.
Add water and spaghetti to the pan. Spread the spaghetti out slightly on the top so it’s somewhat submerged, and bring to a boil. Reduce heat to medium-low, cover, and simmer until al dente, about 15 minutes. Stir frequently.
Remove the pan from the heat and stir in the sour cream and shredded Mexican cheese until melted.
Top with sliced tomatoes, jalapenos, and cilantro before serving, if desired.
Notes
Plain Greek yogurt can be substituted in place of sour cream.
This recipe would also work with ground chicken or turkey.
This recipe was only tested with spaghetti so I cannot speak to the cooking time of other pasta or if they will work.