Fish au Gratin

Prep time: 10min
Total time: 50min
Serves: 8
3 tbsp
45 mL
small onion, finely diced
2 tbsp
chopped fresh thyme
30 mL
4 tsp
all-purpose flour
20 mL
1 1/4 cups
2% milk
300 mL
3 tbsp
Dijon mustard
45 mL
1/2 cup
shredded Cheddar
125 mL
2 ½ lb
white-fleshed fish fillets, such as cod, haddock or sole
1.25 kg
1/2 cup
panko or homemade breadcrumbs
125 mL
3 tbsp
finely grated Parmesan
45 mL
1 tbsp
finely chopped fresh chives (optional)
15 mL
Per serving (1/8 of the recipe):
9 g
saturated fat
5 g
11 g
3 g
28 g
80 mg
1 g
360 mg


  1. Preheat oven to 180°C (350°F). Grease an 8 in. (20 cm) square glass or ceramic baking dish; set aside. Melt butter in saucepan over medium heat. Cook onion and thyme about 5 min., or until onion is tender. Sprinkle with flour and stir to coat onion. Cook 1 to 2 min. Gradually whisk in milk until sauce is smooth. Mix in mustard. Reduce heat to medium-low. Simmer 5 to 8 min. until slightly thickened. Remove from heat. Stir in cheese until melted.

  2. Pat dry fish fillets with paper or kitchen towels. Place in prepared baking dish, cutting fish to fit if necessary. Bake 15 to 20 min. until fish is just cooked through, starts to flake and internal temperature reaches 70˚C (158˚F). Remove from oven.

  3. Preheat broiler. Pour cheese sauce overtop fish. Sprinkle with breadcrumbs and Parmesan. Broil 1 to 2 min., or until breadcrumbs are golden brown. Sprinkle with chives, if using. Serve immediately.