Prep ingredients: Preheat oven to 450°F with racks in the top and center positions. Lightly oil a medium baking dish. Halve shallot, then peel and thinly slice lengthwise. Reserve ⅛ cup sliced shallots for salad, then finely chop ¼ cup shallots. Grate mozzarella on large holes of box grater.

Start sauce: Heat 1 tablespoon oil in a small saucepan over medium-high. Add chopped shallots and cook, stirring, until golden, 1–2 minutes. Add tomato paste and cream cheese; break up using the back of a spoon, and cook until cream cheese has softened, stirring occasionally, about 1 minute.

Finish sauce: Whisk in 1¼ cups water and bring to a boil over high and cook, about 1 minute. Season sauce with ¾ teaspoon salt and a few grinds pepper. Remove from heat.

Bake tortelloni: Place tortelloni and peas in prepared baking dish and top with sauce. Shake to distribute sauce and top with mozzarella. Cover baking dish with foil, then bake on the center oven rack until tortelloni begins to soften, about 10 minutes. Uncover, and continue to bake until sauce is thickened, about 8 minutes.

Make dressing: Meanwhile, in a large bowl, whisk 1 tablespoon vinegar with 2 tablespoons oil, and season to taste with salt and pepper. Add sliced shallot to dressing and allow to marinate while tortelloni bakes. Tear lettuce into bite-size pieces.

Broil tortelloni & serve: Remove tortelloni from oven and preheat broiler. Broil on top oven rack until cheese is golden-brown and bubbly, about 30 seconds (watch closely as broilers vary). Add lettuce to dressing and toss to coat. Serve baked tortelloni with salad alongside. Enjoy!