Press thawed puff pastry into a 10.5" x 7.5" removeable bottom tart pan (as seen in the picture) or into a 9" round removeable bottom tart pan; set aside.: The pastry should feel cool and slightly pliable, not sticky; when you press it gently into the pan you will hear a faint rustle as the layers settle. Smooth it into the corners with your fingertips or a small rolling pin, ensuring no thin spots remain, and trim any excess so the edges will brown evenly. This step matters because an even shell bakes uniformly, avoiding soggy or undercooked sections. A common mistake is overworking the pastry which warms the butter layers, causing a dense crust, so if it becomes too soft, chill it for 10 to 15 minutes before continuing. Visually you want an even layer with a little overhang to create a neat rim after baking.
Place sausage, eggs, cream, milk, cheese, sundried tomato, salt and pepper in a bowl and whisk to combine. Pour mixture into prepared pan. Sprinkle sausage and broccoli on top. Place blanched asparagus into mixture and scatter grape tomatoes on top.: As you whisk, the mixture will turn glossy and slightly thick, and the aroma of sausage and cheddar cheese will rise, hinting at the savory depth to come. Pour steadily so the custard nests into the shell without splashing, then press the sausage and chopped broccoli evenly so every slice gets texture. When you place the blanched asparagus across the top, the green will gleam against the pale custard, and the halved grape tomatoes will add red contrast. This assembly order helps delicate vegetables stay visible and prevents heavy ingredients from sinking. Avoid over mixing after pouring, as this can create air pockets that cause the filling to puff unevenly; if bubbles appear, gently tap the pan on the counter to release them.
Bake at 375 degrees F for about 30 minutes or until the center is firm. Let cool for about 10 minutes before serving.: In the oven, the pastry will go from pale to golden, and the filling will rise slightly and then settle as proteins set; you should see the edges set before the center firms. The kitchen will fill with a warm, buttery fragrance and the sound of gentle oven hums. An instant read thermometer inserted near the center should read around 160 degrees F when done, and the top will be lightly golden with no visible jiggle in the center. This timing ensures a custard that is creamy yet fully set; underbaking leaves a runny center, while overbaking makes it dry and rubbery. If the edges brown too quickly, tent the tart with foil to prevent burning while the center finishes cooking. After removing from the oven, cooling for 10 minutes helps the custard finish setting and makes slicing cleaner.
Notes** (1) For a different flavor try using Gruyere or Fontina in place of the cheddar cheese. (2) To make this vegetarian, skip the sausage. (3) The sundried tomatoes are optional, but it does add another layer of flavor.: You will notice subtle changes if you swap cheeses, like a nuttier profile with Gruyere or a creamier melt with Fontina, which can complement the asparagus differently. Skipping the sausage lightens the dish and lets the vegetables shine, useful when serving a mixed group. Sundried tomatoes add concentrated sweet acidity when included, but omit them if you prefer a simpler flavor. The why here is that small swaps affect the balance of fat, salt, and acid in the custard, changing mouthfeel and pairing dynamics. A common slip is not adjusting salt when using different cheeses, so taste cautiously if you alter components.