A flexible paper microwave package in the form of an easily expandable, nontrapping bag (18) is disclosed including a bottom wall (20) and a top wall (22) interconnected together adjacent their circular outer peripheries (20a, 22a) by first and second interconnection portions (26a, 26b). In one preferred form, the top wall (22) is formed from a first portion (22d) having an oval shaped access opening closed by an oval shaped closure portion (22e) interconnected by a seal (40) to the first portion (22d). The bottom and top walls (20, 22) expand into an opposing double domed shape as the food product is being popped, puffed, or expanded in the microwave oven. This domed shape of the bottom wall (22) keeps the food product huddled closer together and enhances the bag (18) to rock to maximize gravimetric separation. The bag (18) provides a serving bowl function when the peelable closure seal (40) has been opened providing access to the interior of the bag (18) and specifically to the popped, puffed or expanded food product located therein. An extension (42) integrally extends from the closure portion (22e) along the major axis of the oval shape. First and second pairs of extensions (54) integrally extend from diametric opposite sides of the bottom and top walls (20,22) and along the major axis of the oval shape. Slits (60,66,74) relieve the constraints of the extensions (54) to creasing and puckering of the bottom and top walls (20,22) as they expand into the opposing double dome shape.