Heat the olive oil in a large skillet over medium-high heat.
Add the sliced onion and cook for 2 to 3 minutes, stirring occasionally.
Add the sliced bell peppers and a pinch of the salt. Stir to combine.
Cook for 7 to 10 minutes, stirring occasionally, until the vegetables are softened and lightly browned around the edges.
If the skillet becomes dry, add a small amount of additional oil as needed.
Stir in the oregano and remaining salt.
Cook for 1 to 2 minutes more, until fragrant.
Remove from the heat and serve immediately.
Christina's Notes
Preheating the skillet before adding the vegetables helps develop better color and flavor.
Onions take slightly longer to soften than peppers, which is why they are added first.
Seasoning in layers creates a more balanced flavor than adding all the salt at the end.
For extra color, use a combination of green, red, yellow, and orange bell peppers.
Store leftovers in an airtight container in the refrigerator for up to 4 days.
Reheat in a skillet over medium heat until warmed through.