Preheat the oven to 400°F (200°C) and prepare a baking sheet.

Heat olive oil in a skillet over medium heat. Add chopped onion and minced garlic; sauté until onion is translucent (about 3-4 minutes).

Stir in diced carrots and celery; cook for another 5 minutes until slightly softened.

Pour in heavy cream and stock, simmering until slightly thickened (3-5 minutes).

Fold in lobster meat and frozen peas; simmer for 5 minutes until heated through.

Remove from heat; stir in thyme, lemon juice, salt, and pepper to taste.

Roll out one pie crust into a 9-inch pie dish, fill with lobster mixture.

Cover with the second pie crust; seal edges and cut slits for steam.

Whisk egg and brush over the top crust.

Bake for 30-35 minutes until crust is golden brown; monitor closely after 25 minutes.

Let cool for 10-15 minutes before serving.