This spaghetti recipe is a "family favorite" according to one online reviewer. The eggs and milk create a rich, creamy sauce that coats the pasta. The key to the creaminess is tempering the eggs - heating them gently so they don't cook too fast and curdle. Do this by slowly whisking in the hot water in which the pasta cooked.
Cook pasta according to package directions. Drain in a colander over a bowl, reserving 1/2 cup hot cooking liquid.
While pasta cooks, cook bacon in a large nonstick skillet over medium heat until crisp. Remove bacon from pan, reserving 1 tablespoon drippings in pan. Discard remaining drippings; set bacon aside. Add garlic to drippings in pan; cook 30 seconds, stirring constantly.
Combine milk, salt, pepper, and eggs, stirring with a whisk. Gradually add reserved hot cooking liquid to milk mixture, stirring constantly with a whisk. Add pasta, milk mixture, and peas to skillet; cook over low heat 3 minutes or until sauce thickens. Add bacon and cheese; stir to combine.