Step 1

Whisk flour and 1/4 cup milk in a small bowl until smooth. Bring the remaining 1/4 cup milk just to a boil in a small saucepan over medium-high heat. Whisk in the flour mixture; simmer, whisking constantly, until slightly thickened, about 1 minute. Remove from heat. Stir in peas, tarragon, lemon zest, lemon juice, salt, pepper and 1 tablespoon chives. Cover and keep warm until ready to serve.

Step 2

Meanwhile, prepare ravioli according to package directions; drain. Divide the ravioli evenly among 2 shallow bowls; top with the sauce, lobster (if using) and the remaining 1/2 tablespoon chives.