Scrub, remove beards of mussels and rinse them under cold water. Place the mussels in a large colander, to drain the water. Thinly slice the onion, celery and leeks.
Melt the butter in a large deep frying pan or a saucepan over medium-low heat. Then add in the onions, celery, leek, curry powder, cayenne pepper, bay leaves, thyme and saffron. Cook and stir regularly for 5 minutes until the saffron bleeds (veggies are a golden yellow colour).
Increase the heat to high and add in the wine, then cook until the alcohol smell disappears. Add in the fish stock and let the mixture come to a boil, then reduce the heat to medium-low. Simmer uncovered for 10 minutes.
Increase the heat to high and bring the mixture to a boil, then add in the mussels and cover for a minute. Using tongs or a slotted spoon, remove all the mussels from the pan and transfer them into a large bowl. Discard any mussels that didn't open. Reduce the heat to low and stir the cream into the pan, then cook gently for 5 minutes. Remove the pan from the heat, then return the mussels to the pan and stir gently to combine. Taste the soup and add salt and pepper if needed.
Notes
(NOTE 1) Mussels - I used Australian Blue mussels that came in a vacuum-sealed bag ready to use. They're kept alive with ocean water and are cleaned prior to packaging. The only thing I had to do was rinse the mussels out in cold water and leave them in a colander to drain out the water. If you're using uncleaned mussels, scrub the shells and pull out their beards before cooking.(NOTE 2) Saffron threads - Pure saffron threads are expensive for just a tiny amount. It's nicknamed 'Red Gold' for a reason! Saffron has a floral, earthy and sweet honey flavour. Supermarkets usually stock saffron near the spice and cooking section. Be mindful of very cheap fake saffron, as you definitely want to avoid these! I bought 100mg (a very tiny amount) for approximately $10 (USD 7).(NOTE 3) Dry white wine is lower in sugar levels than other varieties of white wine. Sauvignon Blanc, Chardonnay and Pinot Grigio are popular dry white wine varieties.(NOTE 4) Fish stock- I used store-bought fish stock, which I found near the beef and chicken stock. You could use your own homemade fish stock.(NOTE 5) Thickened cream (whipping cream) has gelatine added to it and contains 35% milk fat. To maintain a smooth, rich consistency, I don’t recommend using low-fat cream.A Third-Party Application calculated the calories and nutritional information. Please use this as an approximate guide only.Cooking measurements are in Australian standard spoon and cup measurements.