Heat the oven to 350℉/180℃ convection/fan
Make the cheese filling: Tear the burrata in half. Place one half in a mixing bowl.Add the soft cheese, chopped herbs, grated cheddar, milk, salt, and pepper. Mix until combined.
Prep the tomatoes: Thinly slice the large tomatoes and cherry tomatoes.
Prepare the pastry: Roll out the shortcrust pastry sheet. Trim about 2 inches (5 cm) off the long edge and attach that strip to the top edge of the pastry. Press firmly and roll lightly to blend. Cut the largest circle possible from the pastry and place it on the included sheet of parchment paper.
Assemble the tart: Spread the cheese mixture evenly over the pastry circle, leaving a ¾‑inch (2 cm) border. Arrange the sliced tomatoes over the filling, overlapping slightly and filling gaps with cherry tomatoes.
Fold and finish: Fold the pastry border inward over the tomatoes. Brush the crust with beaten egg. Sprinkle a little extra grated cheese over the crust. Drizzle the tomatoes lightly with olive oil.
Bake: Bake at 350°F for 25–30 minutes, until the crust is golden and the tart is cooked through.
Remove excess moisture: If tomato juices pool on top, gently blot with a paper towel.
Finish with burrata: Tear the remaining half of the burrata over the center of the tart. Sprinkle with fresh herbs and black pepper.
Serve: Serve warm with a salad and a drizzle of balsamic glaze.