Tasty One-pot Green Pav Bhaji Recipe

1 tbsp butter
2 tbsp water
1 tbsp ginger, finely chopped
2 tsp garlic, finely chopped
2 green chillies, finely chopped
1 small onion, finely chopped
1 capsicum, finely chopped
1/2 cup green beans, finely chopped
1/2 cup green peas, finely chopped
1/4 cup green onions, finely chopped