Thinly slice the red cabbage (3 minutes). Finely chop the onion and mince the garlic (2 minutes).

Heat 5 ml of olive oil in a large skillet over medium heat. Add the chopped onion and cook until softened (3 minutes). Add the minced garlic and cook for another 1 minute until fragrant.

Add the sliced red cabbage to the skillet. Pour in the apple cider vinegar and water. Stir well, cover, and let it braise over medium-low heat while you prepare the rest of the meal (10 minutes). Stir occasionally.

While the cabbage is braising, prepare the polenta. In a medium saucepan, bring the vegetable broth to a boil (3 minutes). Slowly whisk in the cornmeal, stirring continuously to prevent lumps (1 minute). Reduce heat to low and simmer, stirring frequently, until the polenta thickens and is creamy (5 minutes). Season with salt and pepper.

Pat the trout fillets dry with a paper towel. Season both sides with salt and pepper (1 minute). Heat the remaining 5 ml of olive oil in a separate non-stick pan over medium-high heat (1 minute).