In a mixing bowl, combine cream cheese, jarred horseradish, lemon juice, and chopped chives. Flake in the smoked trout and mix until creamy. Cover and chill for at least 30 minutes.

Thinly slice red cabbage and red onion. Dice the apple and chop parsley. Combine all in a large bowl, dress with red wine vinegar and olive oil, mixing until well-coated.

Whisk together plain flour, milk, eggs, and salt until smooth. Let rest for 15 minutes.

Preheat your oven to 220°C (430°F) with a baking dish and oil. Pour in the rested batter and bake for 20-25 minutes until puffed and golden.

Create a well in the Yorkshire pudding, fill with chilled trout pâté, and top with slaw. Serve immediately with lemon wedges.