How To make Zucchini Curry Eintopf (Zucchini Curry Stew)

1 kilogram zucchini
1 onion
1 garlic clove
30 grams clarified butter
1 tablespoon curry powder
1 can tomatoes
3 tablespoons coconut paste -- (*)
2 tablespoons mustard seed
(*) I cooked 100g dried grated coconut with water in the microwave oven, pureed it and strained it through a sieve. Peel, seed and dice zucchini. Mince onion and garlic. Puree tomatoes together with the juice. Steam onion and garlic in the clarified butter. Stir in curry powder. Add tomatoe puree and cook until it thickens a bit. Dissolve coconut paste in the tomatoe puree. Add diced zucchini and steam for about 30 minutes until
tender. Roast mustard seeds in a pan and sprinkle over the stew.