Set a large skillet over medium heat and add the butter. When the butter is melted, add the diced onion and potatoes, stirring to coat them evenly. Cover the skillet and cook for about 10 minutes, stirring occasionally, until the potatoes are golden and tender enough to easily pierce with a fork.

Sprinkle in the garlic powder, thyme, salt, and pepper. Stir to mix the seasonings into the potatoes and onions. Add the chopped cabbage and stir to combine.

Lower the heat to a gentle simmer, cover the skillet, and let it cook for about 5 minutes. Stir occasionally until the cabbage is tender but still has a bit of crunch.

Adjust seasoning to taste and serve hot.