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Sweet Onion Casserole with Crispy Topping

This casserole is a unique make ahead side dish. Onion is so overlooked as a vegetable, often it just added to dishes rather than being the star of the dish. This easy side dish takes onions and turns them into the BEST kind of casserole - one that is packed with flavor and goes with everything!
Prep Time10 mins
Cook Time55 mins
Total Time1 hr 5 mins
Course: Side Dish
Servings: 8


  • 2.5 lbs sweet onions
  • ½ cup butter
  • ½ tsp salt
  • ¾ cup water can substitute sherry for half of the water
  • 2 tsp sugar
  • 2 tsp balsamic vinegar
  • 1 cup panko breadcrumbs
  • 1 tbsp olive oil
  • 1 tsp chives chopped
  • 1 tsp parsley chopped


  • Preheat oven to 350°
  • Peel and thinly slice the onions.
  • Heat butter in a skillet, add the onions and salt. Stir to coat onions in butter.
  • Cook uncovered over low heat for 30 minutes until the onions are soft but not coloured.
  • Turn up the heat and add water (and sherry if using), sugar, and balsamic vinegar. Let the mixture bubble gently for 10 to 15 minutes until the liquid has evaporated and the onions are meltingly tender.
  • Transfer the onions to a casserole dish.
  • Heat the olive oil in a non stick skillet and add in the breadcrumbs. Cook over medium heat until the start to brown.
  • Remove from heat and sprinkle over the hot onions. Bake for 10 minutes, sprinkle with herbs and serve immediately.