Overnight Egg, Spinach & Hash Brown Breakfast Strata

Ingredients

• 1 tablespoon unsalted butter
• 1 tablespoon extra-virgin olive oil
• 12 ounces tri-color baby creamer potatoes, unpeeled, cut into 1/3-inch slices
• 1 large yellow onion, finely diced
• 1 1/2 teaspoons finely chopped fresh rosemary
• 2 teaspoons white balsamic or champagne vinegar
• 1 pound fresh baby spinach
• 1 1/4 teaspoons sea salt, or to taste
• 1/8 teaspoon freshly grated or ground nutmeg (optional)
• 6 (1-ounce) slices whole grain bread, cut into 4 wedges each
• 12 large eggs
• 2 1/2 cups plain almond or sunflower milk
• 3/4 teaspoon black pepper
• 3/4 cup shredded sharp or extra-sharp Cheddar cheese (3 ounces)
• 3/4 cup shredded or finely chopped Paesanella or Taleggio cheese (3 ounces)