Heat 1 tablespoon olive oil in a large ovenproof skillet over medium-high heat; add the sausage and cook, stirring occasionally, until browned, about 5 minutes. Transfer to a plate using a slotted spoon. Reduce the heat to medium low and add the garlic to the skillet. Cook, stirring often, until lightly browned, about 2 minutes. Add the carrots, fennel, onion, 2 tablespoons water, 1/2 tablespoon thyme and 1/2 teaspoon each salt and pepper. Cook, stirring occasionally, until the vegetables soften, 15 minutes.
Preheat the broiler. Combine the panko with the remaining 1 tablespoon olive oil, 1/2 tablespoon thyme and 1/4 teaspoon each salt and pepper; set aside. Return the sausage to the skillet along with the beans and their liquid, the tomatoes and 1/2 cup water. Bring to a boil, then reduce the heat to medium and gently simmer until the liquid is slightly reduced, about 5 minutes. Sprinkle the panko mixture evenly over the stew and broil until golden, about 4 minutes.