In a large Dutch oven over medium heat, sauté the chopped onion until translucent. Add minced garlic and continue cooking until fragrant.
Add the ground beef to the pot and cook until there is no pink left. Stir occasionally to break up the meat into smaller pieces.
Incorporate the sliced kielbasa sausage into the pot, allowing it to cook alongside the ground beef for a few minutes.
Add the drained peeled and diced tomatoes, diced potatoes, pinto beans (including the liquid), drained corn, diced tomatoes with green chile peppers (with liquid), and frozen mixed vegetables. Mix everything until well combined.
Sprinkle the ground cumin, chili powder, salt, and pepper over the ingredients in the pot. Stir well to ensure the spices are evenly distributed.
Pour in the water and bring the stew to a boil. Once boiling, reduce the heat to low and let it simmer for one hour, allowing the flavors to meld together.
Taste the stew and adjust the seasoning with additional salt and pepper if desired.
Serve the Texas Cowboy Stew hot and enjoy its savory flavors and satisfying textures.