Chop the cabbage into bite-sized pieces. Wash the potatoes (since we don't peel them for this recipe) and dice them into 3/4" or 2cm pieces.
Place a large pot or dutch oven on the stove. Heat butter/oil over medium heat, then add cabbage and potatoes to the pot.
Stir often and cook for 5-10 minutes.
The cabbage should start to soften at this point. Add in thyme, salt, pepper, and flour, stirring well to coat the vegetables in the flour.
Add in about 500ml or 2 cups worth of stock or water. Stir to make sure nothing is sticking to the bottom of the pot.
Cook on medium-low heat (covered) for 15-20 minutes, stirring often to prevent burning to the bottom, and adding more stock/water if it evaporates. We added at least another 100ml or 1/2 cups' worth of liquid, but you may need more or less depending on how quickly your potatoes cook.
While the cabbage and potatoes are cooking, dice the apple and slice the sausage into rounds.
Add apple and sausage to the pot once the potatoes are tender.
Cook for another 5-10 minutes so the apple begins to soften as well. If you need to, add more stock/water to make sure nothing sticks to the bottom of the pot.
Make sure to taste for seasoning, as you may need to add more salt and pepper.
Optionally, but recommended - chop fresh parsley and add to the pot, along with frozen peas. This helps add more freshness and a pop of color as well!
Do a final seasoning check and adjust salt and pepper levels as needed. Serve with bread and enjoy!