Preheat the oven to 375 F and grease a 9x13 inch baking dish.
Cook the breakfast sausage in a large skillet over medium heat for 6 to 8 minutes, breaking it into crumbles until browned. Add the onion and red bell pepper and cook 4 more minutes until softened. Drain any excess grease.
In a large bowl, whisk together the chickpea flour, milk, baking powder, salt, black pepper, garlic powder, turmeric and olive oil until completely smooth with no lumps. Let it rest for 5 minutes.
Spread the thawed hash browns evenly in the baking dish. Scatter the sausage mixture and 1 1/2 cups of the cheddar cheese over the top.
Pour the chickpea batter evenly over everything, pressing lightly with a spatula so it seeps between the layers. Sprinkle the remaining 1/2 cup cheese on top.
Bake uncovered for 40 to 45 minutes until the top is golden, the edges are bubbling and the center is set when gently pressed.
Let rest for 10 minutes, sprinkle with green onions, then cut into squares and serve warm.
