Place the onion, carrots, bell pepper, garlic, and ginger in the slow cooker.
Add the red curry paste, coconut milk, vegetable broth, and tamari. Stir until the curry paste is fully mixed in.
Gently fold in the tofu cubes so they are coated with the sauce.
Cover and cook on low for 6 hours until the vegetables are soft.
Stir in the lime juice right before serving.
Spoon the stew over cooked jasmine rice and top with fresh basil leaves.