• 2 tbsp. chopped cilantro, for garnish
Preheat oven to 450 degrees. Line a rimmed baking sheet with parchment paper.
Combine the tofu, 2 teaspoons oil and ¼ teaspoon salt in a mixing bowl. Gently toss to coat. Transfer to the baking sheet, spreading the tofu in a single layer. Roast until the tofu feels even firmer, about 30 minutes, turning the cubes over about halfway through.
Meanwhile, pour remaining 3 tablespoons oil into a large sauté pan over medium heat. Add the mustard seeds and cook, shaking the pan occasionally, until they pop, 2 to 3 minutes.
Add the onion, garlic, ginger, turmeric, cumin, cardamom, chile powder, black pepper and the remaining ½ teaspoon salt; cook until fragrant, 2 minutes. Stir in the peanut butter until well incorporated, then stir in the tomatoes and their juices, jalapeño, broth, mustard greens and bay leaves. Once the mixture starts to boil, reduce the heat to medium-low, partially cover and cook, stirring occasionally, for 20 minutes.