Abstract: Method and apparatus for the controlled cooking of food solids in glass containers while overcoming the problem of thermal shattering of the glass is disclosed. By using a tunnel furnace with heated air directed into and around the glass container, the glass can be tempered and retempered according to the needs of the ingredients to be added. Foods such as meat can be cooked in the glass container without loss of beneficial by-products. By using this method and apparatus, solid foods can be added separately from liquid foods to thereby control amount of material packed. This procedure also allows for the frozen addition of the solids to thereby avoid disintegration of the solid if soft and subject to abrasion.