Place a small amount of medium paste solder on the seam inside of the oval. With the top of the side wall/bezel facing forward toward you, place the oval on a soldering surface. Heat until the solder flows. Immediately use a pick to tip the oval over so the bottom is on the soldering surface and heat the outside of the oval, drawing the solder to the outside and up to the top of the seam. After a few seconds, the soldered pieces can be placed the on a bench block to cool. The bench block acts as a heat sink and draws the heat out of the pieces. To make it easy to determine which is the bottom of the side wall/bezel, mark a down facing arrow on the outside of each oval.
Pro Tip: Because Argentium will start to melt before hard paste solder flows, medium paste solder is used in this step. If using sterling silver, hard paste solder should be used in this step.