How to Make It
Place tofu on a plate lined with paper towels; top with another layer of paper towels and a plate or a skillet. Press and let stand 20 minutes.
Heat coconut oil in a large nonstick skillet over medium-high. Add tofu blocks, and cook until lightly browned on all sides, 8 to 10 minutes. Set aside.
Whisk together coconut milk, vegetable stock, lime juice, tomato paste, chili paste, sugar, fish sauce, and curry powder in a slow cooker. Add bell peppers, onions, lemongrass, ginger, garlic, and serrano chile; stir to combine. Top with tofu blocks. Cover and cook on low until vegetables are tender, 6 to 8 hours.
One hour before serving, carefully transfer tofu blocks to a cutting board, and cut into 1/2-inch slices. Return sliced tofu to slow cooker. Remove and discard lemongrass. To serve, ladle curry into 8 bowls; top evenly with bean sprouts and cilantro. Serve with lime wedges.