In large pot of boiling salted water, cook noodles according to package instructions until just tender. Drain and chill under cold water; drain well.
Meanwhile, in skillet, heat oil and butter over medium-high heat. Add pancetta and caraway seeds; saute until pancetta starts to render some fat. Add onions and sa< cook, stirring often, until golden brown, about 12 minutes. Remove from heat.
In large bowl, whisk together eggs, milk, pepper and nutmeg; stir in noodles to coat. Stir in onion mixture and half of the cheese. Place in buttered 13- x 9-inch (33 x 23 cm) baking dish. Sprinkle with remaining cheese. Bake, uncovered, in 375°F (190°C) oven until lightly browned, about 30 minutes.