Preheat oven to 400°F.

Place puff pastry on a flour-dusted countertop or large cutting board. Using a rolling pin, roll the pastry into a rectangle approximately 10 by 16 inches (some packages will already be a rectangle, others you’ll need to pinch together).

Transfer pastry to a baking sheet and brush with olive oil. Spread the minced shallots over the pastry in a thin, evenly distributed layer.

Season with a sprinkle of salt and pepper (the salt helps draw out the moisture in the shallots, so that they soften instead of browning). Bake for 6-8 minutes, until the pastry just begins to brown and puff.

Once the pastry has baked for 6-8 minutes, remove it from the oven.

Sprinkle the cheese and thyme over the shallots and spread the asparagus out over the tart base, making sure to leave a rim of uncovered crust all the way around.

Return to the oven and bake for 10-15 minutes, until the edges of the pastry have browned and puffed up, and the asparagus is tender.

Let cool for 10-15 minutes prior to cutting. Serve warm or at room temperature.