Preheat your oven to 400°F (200°C). Spread the cubed sweet potatoes evenly on a baking sheet, drizzle with 1 tablespoon of olive oil, and season with salt and pepper. Roast for about 25-30 minutes until they are tender and slightly caramelized around the edges.
Meanwhile, cook the wild rice in plenty of boiling salted water according to package instructions, usually about 40-45 minutes until fluffy and chewy. Drain and set aside.
In a small skillet, heat the remaining tablespoon of olive oil over medium heat. Add the chopped sage leaves and cook for about 1-2 minutes until fragrant and slightly crispy. Remove from heat and set aside.
Combine the breadcrumbs with the melted butter and the crispy sage, stirring until the crumbs are evenly coated and fragrant. Spread the breadcrumb mixture on a small baking sheet and toast in the oven for 5-7 minutes until golden brown.
In a large mixing bowl, gently fold the roasted sweet potatoes and cooked wild rice together. Stir in the shredded cheese and Drizzle with a little of the sage-infused oil for extra flavor.
Pour the rice and sweet potato mixture into an oven-safe baking dish, spreading it out evenly. Sprinkle the toasted sage breadcrumb mixture over the top, creating a crunchy crust layer.
Bake the casserole in the preheated oven for about 15 minutes, until the top is bubbly and the crumbs are crisp and browned.
Remove from the oven and let sit for a few minutes to settle. Serve warm, enjoying the contrast of tender vegetables and crunchy topping.
