1 – 14-oz. package firm or extra-firm tofu, patted dry, cut into ½” cubes
2 medium onions, coarsely chopped
1/2 cup cup red curry paste
2 large zucchini, cut into ½” pieces
1 large or 2 small Japanese eggplant, cut into ½” pieces
8 oz. green beans, trimmed, cut into 1” pieces
113.5-oz. can unsweetened coconut milk
Lime wedges, cilantro leaves with tender stems, and coarsely chopped salted, roasted peanuts (for serving)
Heat 2 Tbsp. oil in a large skillet, preferably nonstick, over medium-high. Add tofu in a single layer and cook, turning over once, until cooked sides are golden brown, about 4 minutes. Transfer to paper towels to drain. Season with salt.
Heat remaining 2 Tbsp. oil in a large pot or high-sided skillet over medium-high. Add onions and a generous pinch of salt and stir to coat. Cook, stirring often, until softened, about 4 minutes. Stir in curry paste and cook, stirring often, until darkened in color, about 2 minutes. Add zucchini, eggplant, and green beans and cook, tossing to coat, until vegetables are softened and starting to brown in spots, 5–7 minutes. Pour in coconut milk.
Add tofu to pot and stir gently to combine. Cook until warmed through, about 3 minutes. Season with more salt if needed.
Divide curry among bowls and add a generous squeeze of lime juice to each. Top with cilantro and peanuts.