Preheat your oven to 400°F and line a baking sheet with foil. Lay the bacon strips flat on the sheet and bake for 20 minutes until crispy. While the bacon cooks, mince your garlic cloves and finely chop the fresh chives, setting them aside. Grate both the sharp cheddar and Colby Jack cheeses (freshly grating ensures better melting than pre-shredded). Once the bacon is done, transfer it to a paper towel-lined plate and blot away excess grease, then chop into bite-sized pieces.

Lower your oven temperature to 350°F. Cut the Italian bread into 1-inch cubes and generously grease a 9x13-inch baking dish. Add all the bread cubes to the dish, then scatter the chopped bacon from Step 1, both grated cheeses, minced garlic, and chopped chives over the bread. Toss everything together gently but thoroughly to distribute the ingredients evenly throughout the dish.

In a large bowl, whisk together the room-temperature eggs, half and half, heavy cream, salt, black pepper, and Dijon mustard until well combined and smooth. This custard mixture should be homogeneous with no streaks of egg white. Pour the egg mixture evenly over the bread and cheese mixture in the baking dish, then gently press down any bread cubes that are still poking above the surface to ensure they soak up the custard. I like to let this sit for a few minutes before baking so the bread can start absorbing the liquid, which creates a better texture.

Cover the baking dish tightly with foil and bake at 350°F for 20-22 minutes. This initial covered bake creates a gentler cooking environment, allowing the custard to set without the top browning too quickly. Remove the foil and continue baking for another 30 minutes until the top is golden brown and the center is set but still slightly jiggly when you gently shake the dish—it will continue cooking slightly as it cools. The strata should be puffed and lightly browned on top.

Remove the strata from the oven and let it cool for 5-10 minutes. This resting period allows the custard to set fully and makes it easier to cut and serve. I find that letting it rest also helps the flavors meld together better. Garnish with fresh chives if desired for a pop of color and fresh onion flavor, then cut into portions and serve warm.