Heat the butter in a 10-inch, oven-safe skillet over medium heat. When the butter is sizzling, add the onion, carrots, and celery. Sauté for 7-10 minutes, stirring often, or until the vegetables are soft. Stir in the garlic. Cook for a minute, stirring constantly, or until the the garlic is very fragrant.
Mix the hot water and Yondu seasoning. Sprinkle the flour over the vegetables. Pour the Yondu broth over the vegetables in a thin stream, stirring constantly as you go to prevent lumps of flour from forming. Add the milk to the skillet, followed by the chickpeas, salt, and pepper. Stir well.
Allow the chickpeas to simmer for 3-4 minutes, or until the sauce is thickened. Taste and adjust salt and pepper as needed. Remove the skillet from heat.
To make the biscuit topping, combine the flour, baking powder and salt in a large mixing bowl. Using a pastry cutter (or by hand), cut in the vegan butter. The butter should be in pea-sized pieces. Pour the non-dairy milk into the center of this mixture. Mix with a spatula or spoon until the dough is moistened throughout and minimal flour remains at the bottom of the mixing bowl. You should have big clumps of dough (not a single mass, but not crumbs, either). Sprinkle this biscuit topping over the chickpea and vegetable mixture and transfer the cobbler to the oven.
Bake the cobbler for 40 minutes, or until the filling is bubbling and the biscuit topping is turning golden. Allow the cobbler to cool for a few minutes before serving.
If you don't have Yondu seasoning at home, you can substitute 1 1/2 cups vegetable broth of choice.