Step 1: Preheat the Oven

Place a rack in the center of your oven and preheat it to 350°F. Lightly coat a deep 9-inch pie dish with nonstick spray to prevent sticking.

Step 2: Prepare the Mix-Ins

Before assembling the quiche, prepare your chosen mix-ins. If using chicken, cook and shred it in advance. For ground beef, season and cook it thoroughly. If incorporating vegetables, sauté them lightly to remove excess moisture and enhance their natural flavors.

Example: If making a broccoli and chicken quiche, sauté chopped broccoli florets in a small amount of olive oil until slightly tender, about 5 minutes. Set aside to cool before adding them to the quiche.

Step 3: Make the Egg Mixture

In a large mixing bowl, whisk together the eggs, whole milk, half-and-half, salt, black pepper, Dijon mustard (if using), and nutmeg (if using). Ensure the mixture is well combined and slightly frothy.

Step 4: Assemble the Quiche

• Evenly scatter the prepared mix-ins across the bottom of the greased pie dish.
• Sprinkle the grated cheese over the mix-ins, ensuring even distribution.
• Carefully pour the egg mixture over the top, allowing it to fill the spaces between the mix-ins.
• Sprinkle chopped chives over the top for a fresh finish.

Step 5: Bake the Quiche

• Place the pie dish on a rimmed baking sheet to catch any spills.
• Bake for approximately 35 minutes, or until the quiche is set in the center. It should appear puffed and golden around the edges.
• To test for doneness, insert a thin, sharp knife into the center; if it comes out clean and the eggs are fully set, the quiche is ready.

Step 6: Cool and Serve

• Let the quiche cool for a few minutes before slicing.
• Cut into wedges and serve warm.