Preheat your oven to 375°F (190°C). Dice Yukon Gold potatoes, red bell pepper, and onion into ½-inch cubes and soak the potatoes in cold water for 5 minutes. Drain and pat dry before use.

In a large skillet over medium-high heat, crumble and brown the pork breakfast sausage for about 6-7 minutes until fully cooked. Remove from skillet and set aside.

In the same skillet, melt a tablespoon of unsalted butter. Add the drained potatoes, bell pepper, and onion, sautéing for about 8 minutes until tender and lightly golden.

In a large mixing bowl, whisk together large eggs, whole milk, sea salt, black pepper, smoked paprika, and half of the cheddar cheese. Add maple syrup, Dijon mustard, and apple cider vinegar, mixing until smooth.

Grease a 9-x-13-inch baking dish. Layer the sautéed vegetables and sausage evenly, pour the egg mixture over it, and top with remaining cheddar cheese and fresh thyme.

Bake in the preheated oven for 30-35 minutes, until the center is set and the top is golden brown.

Let the casserole rest for 5-7 minutes before serving warm with your favorite breakfast sides.