Place a Dutch oven or large heavy-bottomed pot over medium heat.
Add the chopped onion to the pot and sauté until it begins to soften.
Add the ground beef to the pot.
Cook the ground beef until fully browned and no pink remains, breaking it apart as it cooks.
Drain excess grease from the pot, if necessary.
Add the sliced kielbasa sausage to the browned beef and onion mixture.
Stir to combine and cook for several minutes, allowing the sausage to warm through.
Add the drained peeled and diced tomatoes to the pot.
Add the diced potatoes.
Add the pinto beans with their liquid.
Add the drained whole kernel corn.
Add the diced tomatoes with green chile peppers, including their liquid.
Add the frozen mixed vegetables.
Stir all ingredients until evenly combined.
Add the ground cumin, chili powder, salt, and black pepper.
Stir thoroughly to distribute the seasonings throughout the stew.
Pour in the water.
Increase the heat and bring the mixture to a boil.
Once boiling, reduce the heat to low.
Simmer the stew for approximately 40 minutes, stirring occasionally.
Continue cooking until the potatoes are tender and the flavors are well combined.
If a deeper flavor or softer texture is desired, simmer for up to 1 hour, adding a small amount of water if needed.
Taste the stew and adjust the salt, black pepper, cumin, or chili powder as desired.
Remove the pot from the heat.
Serve warm.