Ingredients

• 4 x 150–180g / 5–6 oz fish fillets, about 1.5 cm / 1/2" thick, skinless and boneless (Note 1)
  
• 50g / 4 tbsp unsalted butter
• 1/4 cup heavy/thickened cream (See Note 2 for alternatives)
  
• 1–2 garlic cloves, minced
• 1 tbsp Dijon mustard
• 1 1/2 tbsp lemon juice
• Salt & pepper
• 1 1/2 tbsp eschallots (French onion), finely chopped (Note 3)
  
• Fresh parsley and lemon slices, for serving

1. Heat the oven to 200°C / 390°F.
2. Arrange the fish in a baking dish, leaving a little space between each piece. Season both sides with salt and pepper.
3. In a microwave-safe jug or bowl, combine the butter, cream, garlic, mustard, lemon juice, and a pinch of salt and pepper. Microwave twice for 30 seconds, stirring between each burst, until the mixture is smooth and melted.
4. Scatter the eschallots over the fish, then pour the warm sauce evenly across the fillets.
5. Bake for 10–12 minutes, or until the fish is just cooked through. Move the fish to plates, spoon the pan sauce over the top, and finish with parsley and lemon wedges if you like.

1. Choosing fish:
   Fillets or cutlets/steaks around 1.5–2 cm thick work best because they cook quickly and stay tender.
   Great options include Ling, Tilapia, Snapper, Barramundi, Silver Dory, John Dory, Basa, Hoki, Perch, and Flathead.
   Very lean fish (like tuna or swordfish) can be used but monitor closely to avoid overcooking.
   Avoid salmon (fat causes the sauce to split), extra-thin delicate fillets like Dover sole, or small whole fish.
   If your fillets are thicker, the sauce may need a splash of water at the end to thin it slightly.
   For frozen fish, thaw fully and pat dry—frozen fish releases more liquid, which may loosen the sauce (see Note 4).
2. Cream swaps:
   Evaporated milk works as a lighter option. If using light cream, add an extra 2 tsp Dijon mustard for richness.
3. About eschallots:
   Known as French onions in Australia and simply shallots in the US. You can substitute the white part of green onions or very finely minced regular onion.
4. Sauce texture:
   The sauce is meant to be light—not thick like gravy—but it shouldn’t be watery. The exact consistency varies depending on how much liquid your fish releases. To thicken, remove the fish and return the dish to the oven for a few minutes, watching closely.