From Betty Crocker I think. Could also use ciabatta bread, or whatever bread like that you might have on hand. Could also play around with whatever cheese you have on hand. Time listed does NOT include sitting time in fridge.
Spray 13x9-inch (3-quart) glass baking dish with cooking spray. In 10-inch skillet, melt butter over medium-high heat. Add spinach, bell peppers and leeks; cook 4 to 5 minutes, stirring frequently, until crisp-tender. Remove from heat.
In baking dish, layer the ham, the spinach mixture, 1 cup of the Cheddar cheese and the bread. In large bowl, beat eggs, milk, mustard and pepper with wire whisk until blended and pour over bread. Sprinkle with remaining Cheddar cheese and the Italian cheese blend. Cover with foil; refrigerate at least 4 hours but no longer than 24 hours (overnight is great).
Heat oven to 325°F Bake loosely covered 40 minutes. Uncover; bake about 30 minutes longer or until top is golden brown and knife inserted in center comes out clean.