Preheat oven to 375°F (190°C). Lightly oil casserole dish.
Cook wild rice in vegetable broth until tender, about 30 minutes.
In skillet, heat olive oil. Sauté onion, carrots, celery, and mushrooms until soft.
Sprinkle flour into skillet, stir well. Slowly whisk in almond milk to create creamy sauce.
Stir in garlic powder, thyme, salt, and pepper. Simmer until thickened.
Combine rice, chickpeas, vegetables, and sauce in casserole dish. Mix well.
Bake uncovered 25–30 minutes until top is lightly golden and bubbling.
Rest 5 minutes before serving.