Strata is a baked bread and egg casserole served for breakfast or brunch. This a quick and easy version that could be prepared any time of day as a one-pot meal. The strata can be prepared in a single skillet by building it in steps. Sauté onions, add the bread, and finally the eggs and asparagus, which have been par-cooked in the microwave. The skillet is then slid into an oven to cook through. Tangy, herb-and-garlic-flavored Boursin cheese adds big flavor easily.