How to use onions – Ultimate Meal Prep for Deep Flavor
If you buy groceries in bulk (especially in the US), you may have experienced onions becoming soft before using them up.
This easy caramelized onions recipe is the perfect solution.
Cooking onions slowly can transform them into rich, sweet, and deeply flavorful ingredients that can be stored and used at any time. This method is widely used in Korea as the flavor base for various dishes.
Even for the same dish, the depth of taste varies depending on the presence or absence of onion caramelized.
✔️ You who have difficulty saving onions
✔️ You looking for a kick for the depth of taste
✔️ You’re looking for something to do because you have a lot of time
Try the onion caramelized!
👉 Make once, use for weeks.
⚠️ Important:
This recipe requires time and patience.
If you are in a hurry or planning to go out soon, do not start this recipe.
👉 Total cooking time can take 40–60 minutes or more depending on quantity and heat control.
🛒 Ingredients
- 6 large onions (about 1.2–1.5kg)
- 2–3 tbsp vegetable oil (30–45ml)
👉 Optional (Western-style version):
- 1 tbsp butter (14g)
→ Adds richness and works well with pasta, steak, and soup
🔪 Preparation
- Wash and peel the onions.
- Slice onions as thinly as possible (2–3mm thickness).
👉 Important:
Thinner slices = faster moisture evaporation + better caramelization.
🍳 How to Make Caramelized Onions
- Heat a large pan over high heat.
- Add 2 tbsp oil and coat the surface.
- Add all sliced onions.
- Stir constantly for 5–10 minutes until onions release water.
- Continue cooking on high heat for 15–20 minutes, stirring frequently.
👉 At this stage, onions will release a large amount of liquid.
- Keep cooking until most of the moisture evaporates.
- Once water is gone, continue stirring and scraping the bottom.
- Cook for another 20–30 minutes until onions become deep golden brown.
👉 Total cooking time: 40–60+ minutes
⚠️ Important Cooking Notes
- The volume will reduce dramatically after cooking
👉 6 onions → about 1/4 of the original volume
👉 Recommendation:
Always prepare more onions than you think you need
- Stir frequently to prevent burning
- If edges start burning:
- Add 1 tsp oil (5ml)
- Or reduce heat slightly
⚠️ Burnt onions will taste bitter
🧈 Butter Version (Western Style)
Add 1 tbsp butter during the final 10 minutes:
- Creates a richer, slightly creamy flavor
- Perfect for:
- Pasta
- Steak toppings
- Onion soup
- Sandwiches
👉 This makes it ideal for Western recipes using caramelized onions
🧊 Storage & Meal Prep
✔️ Refrigerator
- Store in airtight container
- Use within 5–7 days
✔️ Freezer (Recommended)
- Flatten in a zip bag
- Divide into portions
- Freeze up to 1–2 months
👉 Use small portions anytime — perfect for meal prep
🍽️ How to Use Caramelized Onions
- Curry (deep umami boost)
- Soup (Potato soup, onion soup)
- Pasta
- Steak (garnish)
- Chicken dishes
👉 Just one spoon adds deep flavor instantly
🥗 Why This Recipe Works
- Prevents food waste
- Perfect for bulk grocery shopping
- Saves time in future cooking
- Adds natural sweetness without sugar
- Works in both Korean and Western dishes
❓ FAQ
Q1. Why are my onions not browning?
All the moisture from the onions has dissipated and you have to stir-fry enough to turn them brown. If you cut them thick or have a lot, you should fry them longer!
Q2. Can I make this faster?
High heat helps, but rushing may burn onions instead of caramelizing them.
Slice onions as thinly as possible and use a wide pan to help more.
Q3. How much does the volume reduce?
About 70–80% reduction after cooking.
Here’s another blog of mine. It’s written in Korean!
https://blog.naver.com/emma_513/223027263300
Next time, I will explain the recipe for making Korean curry using caramelization onions!