Bento Box Ideas: Sweet & Sour Stir-Fry + Sides

In this post, I’m sharing simple, real-life bento ideas—what to pack, how to pack it, and practical tips to make bento prep easier and more enjoyable. Using leftovers is a big time-saver, and I highly recommend it! Pack your lunch and enjoy a tasty meal at work or school!

Looking for more? Take a look at these tasty bento ideas!

🍱 What’s in This Bento

Rice, three dishes, and garnishes. All of these components were left over from the previous day or staple items in the fridge.

Sweet & sour atsuage and veggie stir-fry
Homemade tofu-saba fish balls
Quick pickles (napa cabbage, cucumber, and wakame)
Steamed rice (underneath the stir fry)
Garnishes: umeboshi, shiso leaves, radish sprouts

Prepping & Leftovers

The sweet & sour stir-fry, tofu-saba fish balls, and quick pickles were all leftovers from dinner the day before.
The stir-fry was made with atsuage, bell peppers, and carrots, simmered in a quick sauce of vinegar, sugar, soy sauce, and ketchup.
The tofu-saba balls were prepared in advance using mashed tofu, canned saba (mackerel), hijiki seaweed, egg, soy sauce, and panko, then cooked in the oven.
The pickles were a simple mix of cucumber, napa cabbage, and wakame, lightly seasoned with salt, vinegar, and a touch of sugar, similar to a pickled daikon recipe.
I always keep frozen rice on hand—just microwave a portion in the morning. (See how to cook and store rice.)

How to Pack Bento: Step-by-Step

Here’s the plan: spread rice over about 80% of the bento box, place the stir-fry on top of the rice, then fill the remaining space with the other side dishes.

Step 1

Reheat leftovers, then let them cool completely before packing to avoid condensation and spoilage.

Step 2

Place rice into one side of the bento box, leaving room for side dishes. Place the sweet & sour stir-fry on top.

Step 3

Add the tofu-saba balls to an open corner of the box. Then, use a small cup or divider to tuck the pickles in.

Step 4

Place the umeboshi in an open space, and finish with a garnish of fresh radish sprouts. Done!

Packing Tips

Bento is usually packed in the morning and eaten later at the office or school. Since it sits at room temperature for several hours, it’s important to pack it in a way that keeps the food safe and fresh, especially during hot weather. Here are some simple tips to help!

Reheat leftovers thoroughly to kill any bacteria that could cause spoilage.
Cool all items completely before sealing the bento box to prevent condensation and reduce the risk of bacterial growth.
Shiso leaves and umeboshi aren’t just flavorful—they also have natural antibacterial properties, making them great additions to any bento.
Drain excess moisture from high-water items, such as pickles, using paper towels before packing.
Use dividers or silicone cups to keep wet foods (like pickles or saucy dishes) separate from dry foods like rice to maintain freshness and texture.

Bento Carrying Tips

Once everything is packed, wrap your bento and chopsticks in a cloth—it’s not only handy for carrying, but can also be used as a placemat when it’s time to eat.

If you’re packing the bento during warm weather and it will sit at room temperature for several hours, be sure to use an ice pack (you can find cute ones at Daiso, a 100 yen shop) or an insulated lunch bag to keep it fresh and safe.

Itadakimasu!

Time for lunch! Whether you’re packing for yourself or your kids, there’s something so satisfying about opening a well-packed bento box.

I love it when my kids come home with an empty bento and say, “Oishikatta yo!” (It was delicious!). Moments like that make all the prep totally worth it. 💛