Peel and thinly slice the onions.
In a large skillet, heat butter and olive oil over medium-low heat.
Add sliced onions and sprinkle with salt. Stir well to coat.
Cook slowly, stirring occasionally, for 30–40 minutes. Reduce heat if onions start to burn.
If the pan becomes too dry, add a splash of water or broth and stir to loosen browned bits.
For deeper flavor, stir in sugar halfway through cooking. Continue until onions are golden brown and jammy.
Remove from heat and let cool slightly. Use immediately or store in the fridge for up to 5 days.
Prep Time: 10 minutes | Cook Time: 35 minutes | Total Time: 45 minutes
Kcal: Approx. 90 per 1/2 cup | Servings: 6
