A strata, especially this one that can be prepared the day before, is a brilliant idea for feeding a house full of guests. Hot Italian sausage balances the sweetness of the sweet potatoes and gives this healthy breakfast casserole a kick.
Coat a 9-by-13-inch baking dish with cooking spray.
Combine sweet potatoes and 2 tablespoons water in a medium microwave-safe bowl. Cover and microwave on High until just tender, 3 to 5 minutes. Drain any remaining water.
Heat oil in a large skillet over medium heat. Add sausage and cook, stirring occasionally and crumbling with a wooden spoon, until cooked through, about 5 minutes. Using a slotted spoon, transfer the sausage to a plate.
Add onion to the pan and cook, stirring occasionally, until soft and starting to brown, 5 to 8 minutes. Add bell pepper and cook, stirring occasionally, until soft, 2 to 4 minutes. Add garlic and fennel seeds and cook, stirring, for 1 minute. Add kale and the remaining 2 tablespoons water; cook until wilted, about 1 minute. Stir in the sweet potato, the sausage and salt. Remove from heat.
Spread half the sweet potato mixture in the prepared baking dish. Top with 3 cups bread. Repeat with the remaining sweet potato mixture and bread.
Lightly whisk eggs in a large bowl. Add milk and gently whisk to mix. Pour the egg mixture evenly over the casserole and press the bread down into the custard with the back of a spoon. Coat a piece of foil with cooking spray and cover the strata. Refrigerate for at least 1 hour or up to 1 day.
Preheat oven to 350 degrees F.
Bake the strata, covered, for 30 minutes. Uncover and sprinkle with cheese. Bake, uncovered, until the custard is set and the cheese is melted, 30 to 40 minutes more. Let stand for 15 minutes before serving.
To make ahead: Prepare through Step 6 and refrigerate for up 1 day. Let stand at room temperature while oven preheats before baking (Steps 7 to 8).
1 starch, 1/2 high-fat protein, 1/2 medium-fat protein, 1/2 reduced-fat milk, 1/2 vegetable