Preheat the oven to 425ºF.
Place the mushrooms, carrots, and fennel on a large baking sheet and add 3 tablespoons oil, ¼ teaspoon salt, and lots of pepper. Toss to coat, arrange in a single layer, and roast until golden brown, about 25 minutes, stirring once halfway through cooking.
Meanwhile, heat a tablespoon of oil in a large high-sided skillet or Dutch oven over medium-low heat. Add the onion, garlic, herbs, paprika, and ¼ teaspoon salt. Cook until the onion is translucent, about 5 minutes.
Add the tomato paste to the skillet, stir to incorporate, and cook for 1 minute.
Add the beans and broth, bring to a simmer, and cook for 5 minutes more.
Meanwhile, make the topping. In a bowl, combine all the topping ingredients and rub together with your fingers to distribute the oil.
When the bears are done, turn the heat off and stir in the roasted vegetables. Transfer the mixture to a 9-by-13-inch casserole dish. Sprinkle with the panko mixture.
Reduce the oven temperature to 400ºF and bake until the topping is golden brown, 20 to 25 minutes.
