Colorful, kid-friendly, and protein-packed—this Vegan Stir-fry with Whole Red Lentils and Ketchup-Based Sauce is a simple Japanese-inspired recipe full of flavor.
This vegan stir-fried vegetables and lentils recipe is inspired by the nostalgic flavor of Japanese omurice-style ketchup stir fry. Instead of using eggs, the dish highlights whole red lentils for plant-based protein and a hearty texture. The addition of onion koji brings out a rich, umami depth without using meat or consomme.
What makes this dish stand out is the balance of flavors—sweet corn and carrots soften the gentle bitterness of green peppers, while the ketchup sauce ties everything together. Since no strong spices are used, this vegan stir-fry is mild enough for kids, yet satisfying enough for adults looking for a healthy vegan dinner.
If you're searching for more whole red lentils recipes, don’t miss my Vegan Bolognese. Both recipes are tomato-based but bring out completely different flavors, showing just how versatile lentils can be.
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🧃Ingredients
Main Ingredients
- Vegetables: Use a colorful mix such as green beans, onions, carrots, boiled corn, and green peppers. The sweetness of corn and carrots balances the mild bitterness of green peppers, making this vegan stir fry recipe flavorful and kid-friendly. You may omit the onions, but I highly recommend keeping both green peppers and corn for contrast and natural sweetness.
- Whole Red Lentils: These hearty lentils are the main protein source in this vegan lentil stir fry. I cook 200 g of lentils in a pressure cooker with 500-800 ml of water. After rinsing well, pressure cook for about 5–8 minutes until tender but still holding shape. Avoid overcooking, as they can turn soupy. If it’s your first time cooking lentils, start with 5 minutes and adjust as needed. Buy whole red lentils here (Amazon).
Seasonings
- Onion Koji: The secret to this Japanese-inspired vegan stir fry. Onion koji is a natural, additive-free seasoning that enhances umami, making it a perfect substitute for consomme in plant-based cooking. Learn how to make it here.
- Ketchup: The nostalgic base of this dish. Combined with onion koji, it creates a rich, savory-sweet ketchup stir-fry sauce reminiscent of omurice.
- Salt: Helps draw out the natural sweetness of vegetables while stir-frying.
- Oil: Just enough to sauté the vegetables. Any neutral oil works well.
For exact amounts, please check the printable recipe card👇
🥢Instructions
- Preparation: Wash and cut all vegetables into small cubes, roughly the size of corn kernels. This keeps the texture uniform and helps the vegan stir-fry cook evenly.
- Stir-fry: Heat a little oil in a pan (a Japanese yukihira pan works perfectly). Add the chopped vegetables with a pinch of salt, then stir quickly. Cover with a lid and let them steam over low heat for about 4 minutes, stirring occasionally to avoid burning. This method enhances the natural sweetness of the vegetables.
- Seasoning: Add ketchup and onion koji to the vegetables. Stir gently so the flavors coat evenly. This combination creates the nostalgic Japanese-style ketchup stir fry sauce that makes the dish unique.
- Combine: Finally, add the cooked whole red lentils. Mix everything together gently so the lentils keep their shape while absorbing the sweet-and-savory ketchup-based sauce. Taste and adjust salt if needed, then serve warm.
💡 Tips for the Best Vegan Stir Fry
- Cut evenly: Keeping the vegetables the same size ensures even cooking and a better mouthfeel. This makes the vegan stir fry recipe look more colorful, too.
- Balance sweetness and bitterness: Sweet corn and carrots soften the flavor of green peppers. This contrast is what makes the dish taste like a nostalgic Japanese-style ketchup stir fry.
- Don’t overcook lentils: Whole red lentils should stay tender but not mushy. Overcooking will make them soupy, so check them early.
- Season gently: Onion koji is naturally salty and rich in umami, so taste before adding extra salt.
- Make it heartier: For a full meal, serve the stir-fried veggies and lentils over rice, quinoa, or even pasta for a healthy vegan dinner.
🥡 Storage & Meal Prep
This vegan lentil stir fry keeps well for meal prep. After cooling completely, transfer leftovers into an airtight container:
- Refrigerator: Store for up to 3 days. For best results, cook the stir-fry slightly looser than usual so the sauce stays glossy and moist when reheated gently in a pan.
- Freezer: You can freeze for up to 2 weeks. Thaw in the refrigerator before reheating. The lentils may soften a bit more, but the flavor remains delicious.
- Lunchbox-friendly: Because it’s not too saucy, this dish works well for bento or packed lunches.
💭 FAQ
It’s best to use whole red lentils for this recipe because they hold their shape during stir-frying. Split red lentils cook faster and may turn mushy, so the texture will be quite different.
If you don’t have onion koji, you might try substituting with something simple like a vegetable bouillon cube, or even a touch of miso paste or soy sauce. I haven’t tested these substitutions myself, so the flavor won’t be exactly the same—but they could still bring a pleasant umami depth to your cooking.
Yes! Since the seasoning is mainly ketchup and vegetables, this dish is naturally mild and sweet. Adding corn and carrots makes it even more appealing for kids who usually dislike bitter flavors.
Absolutely. Both ketchup and onion koji are typically gluten-free (just check the labels). Serve the vegan lentil stir fry with rice or quinoa for a wholesome, gluten-free vegan dinner.
This healthy vegan stir fry can be served on its own, but I recommend pairing it with steamed rice for a Japanese-style meal or with pasta for a Western twist. It also makes a great bento or lunchbox option.
If you try this recipe, please share your thoughts in the COMMENTS 🐒. Also feel free to ask any questions or leave any requests!
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📖 Recipe Card
Vegan Stir-fried Veggies & Whole Red Lentils with Ketchup Sauce
Equipment
- kitchen knife
- cutting board
- pot
- wooden spatula
Ingredients
Vegetables
- 60 g green pepper
- 40 g green beans
- 50 g corns (boiled)
- 30 g carrot
- 30 g onion (optional)
Seasoning for sauteing vegetables
- 1 teaspoon oil
- salt (a pinch)
Seasoning
- 2 teaspoon onion koji
- 2 tablespoon ketchup
Beans
- 250 g whole red lentils (cooked / see NOTES)
Instructions
- Preparation: Cut the vegetables into cubes roughly the size of a corn kernel.60 g green pepper40 g green beans50 g corns30 g carrot30 g onion
- Stir-fry: Heat oil in a pot, add vegetables and a pinch of salt. Stir quickly, then cover and cook on low heat for 4 minutes, stirring occasionally to prevent burning.1 teaspoon oilsalt
- Seasoning: Add onion koji and ketchup, then mix briefly.2 teaspoon onion koji2 tablespoon ketchup
- Add beans: Stir in cooked lentils. Simmer until your preferred consistency is reached, then remove from heat. Serve with rice.250 g whole red lentils
Notes
- Rinse 200 g of lentils well.
- Add them to a pressure cooker with 500-800 ml (adjust depending on lentil age/texture) water.
- Cook under pressure for 5–8 minutes, then release pressure and check texture.
- If still crunchy, simmer with the lid open until soft.
💬Did you try this recipe? Let me know how it turned out in the comments— or mention #vegin_vegan_vegun or just tag us @veginveganvegun with your delicious creations!
Vegin Vegan Vegun! says
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