In a hot pan with a 1-2 tbsp of olive oil, add chopped aubergine, season with salt and pepper and fry for 5 minutes until it starts to soften and brown.
Lower the heat, add red onion and garlic and cook for a further 2-3 minutes.
Add balsamic balsamic vinegar, tinned tomatoes, tinned butter beans. Stir well and cook for 2-3 minutes more.
Transfer everything to a slow cooker and cook for 3-4 hours on high.
Stir in plenty of chopped mint before serving. Spoon on top of toasted sourdough bread, crumble feta on top (or a vegan alternative) and finish with a drizzle of (optional) balsamic glaze. Enjoy!