1. Optional but recommended: steam the tempeh cubes for 10 minutes before adding to the slow cooker. This removes any bitterness and opens up the pores to absorb more flavor. Just use a steamer basket over boiling water.
2. Place the tempeh cubes, sliced red bell pepper, sliced yellow bell pepper, sliced onion, and minced garlic into the slow cooker. Distribute everything evenly.
3. In a small bowl, whisk together the soy sauce, maple syrup, rice vinegar, ground ginger, and vegetable broth until completely combined. Pour the sauce over the tempeh and vegetables, making sure everything gets coated.
4. Cover and cook on low for 4-6 hours until the tempeh is tender and has absorbed the sauce flavors, or on high for 2-3 hours if you’re short on time. Low and slow gives better results.
5. About 30 minutes before serving, mix the cornstarch with cold water in a small bowl until completely smooth with no lumps. Stir the slurry into the slow cooker and mix gently to incorporate.
6. Cover and cook on high for the final 30 minutes until the sauce thickens and becomes glossy enough to coat the back of a spoon.
7. Taste and adjust seasoning if needed. Serve over steamed rice and garnish generously with chopped green onions and sesame seeds. Enjoy immediately!

Nutrition Information (Per Serving – without rice):

• Calories: 245
• Carbohydrates: 26g
• Protein: 18g
• Fat: 8g
• Fiber: 5g
• Sodium: 780mg
• Iron: 20% DV
• Calcium: 15% DV
• Magnesium: 20% DV
• Vitamin C: 120% DV

This dish delivers substantial plant-based protein from tempeh, complete with all essential amino acids, plus over a full day’s vitamin C from the bell peppers.

Notes:

• Seriously, use low-sodium soy sauce or this will be way too salty after slow cooking
• Steaming tempeh first makes a real difference in flavor absorption and bitterness reduction
• Don’t cut bell peppers too thin or they’ll completely dissolve during the long cooking time
• Make the cornstarch slurry with cold water, not hot, for smooth thickening
• Real maple syrup makes a noticeable difference over artificial pancake syrup

Storage Tips:

• Keep refrigerated in an airtight container for up to 4 days
• Freeze in portions for up to 3 months in freezer-safe containers
• Reheat gently with a splash of broth to restore sauce consistency
• The flavors improve significantly overnight, making this perfect for meal prep

Serving Suggestions:

• Classic Bowl: Serve over steamed white or brown rice with garnishes
• Noodle Bowl: Serve over rice noodles or soba for a different base
• Lettuce Wraps: Spoon into butter lettuce leaves for a lighter option
• Grain Bowl: Serve over quinoa with extra vegetables for added nutrition

Mix It Up (Recipe Variations):

• Spicy Slow-Cooked Tempeh: Add sriracha and red pepper flakes to the sauce
• Pineapple Tempeh Version: Add fresh pineapple chunks for tropical sweetness
• Peanut Tempeh: Stir in 2 tablespoons peanut butter with the cornstarch slurry
• Simple Teriyaki Tempeh: Skip the bell peppers for a streamlined protein bowl

What Makes This Recipe Special:

This slow-cooked tempeh with bell peppers uses the slow cooker’s gentle, sustained heat to do something that quick cooking methods can’t achieve—it allows the tempeh to absorb flavor all the way through rather than just on the surface, transforming this fermented soy product into something deeply seasoned and genuinely satisfying. The teriyaki-inspired sauce strikes the perfect balance between sweet maple, savory soy, and tangy vinegar, creating a glaze that coats every piece beautifully. For anyone skeptical about plant-based cooking, this dish makes a compelling case that vegan food can be hearty, crave-worthy, and completely satisfying without any meat whatsoever.