Prepare pasta according to package directions.

Preheat broiler to high. Grease 4 (2-cup) ovenproof ramekins with 1 teaspoon butter.

Melt 3 tablespoons butter in a large saucepan over medium-high heat. Add onion, thyme, and saffron; sauté 2 minutes or until translucent. Combine flour and 1/2 cup milk in a small bowl, stirring with a whisk. Add flour mixture and remaining 2 cups milk to pan; bring to a simmer. Cook 2 minutes or until slightly thickened. Add lobster and next 4 ingredients; cook 2 minutes. Remove from heat, and stir in cooked penne and cheeses. Spoon mixture into prepared baking dishes.

Melt remaining 2 tablespoons butter in a small microwave-safe dish on HIGH for 30 seconds. Combine melted butter, panko, and chervil in a bowl; toss to coat. Sprinkle panko mixture over top of pasta mixture. Broil 2 minutes or until golden brown. Let stand 5 minutes.