Preheat oven to 375°F. Bake unwrapped frozen pie crust on baking sheet for 10 minutes. Then, remove from the oven and let cool briefly.
Melt the butter in a nonstick pan over medium-high heat. Add diced onion and cook 3–5 minutes or until soft and translucent. Add garlic and stir until fragrant, about 30 seconds. Remove, set aside, and allow to cool slightly.
Whisk eggs in a large bowl until lightly beaten. Whisk in half-and-half, Italian seasoning, and salt/pepper to taste (I add 3/4 tsp salt and 1/4 tsp pepper).
Gently stir in cubed ham and both cheeses. Stir in the cooked onion and garlic.
Leaving pie crust on baking sheet, carefully pour filling into crust (don’t overfill; discard extra if needed). Bake on the lower oven rack for 35–42 minutes, or until set and very slightly jiggly in the center.
Serve warm with optional garnishes as desired.
Video
Notes
Note 1: Use leftover cooked holiday ham or store-bought.Storage: Cool quiche for 2 hours, then store in the fridge for up to 3 days or in the freezer for up to 2 months. To reheat, cover with foil and bake at 325°F until heated through.