A new Field Spell Card that supports Fusion centric Decks appears as the RATE Sneak Preview Promotional card!. Also, a picture of the mat.
Fusion Recycling Plant
Field Spell Card
Once per turn: You can discard 1 card; add 1 “Polymerization” from your Deck or Graveyard to your hand. Once per turn, during the End Phase: You can target 1 monster in your Graveyard that was used as a Fusion Material for a Fusion Summon this turn; add it to your hand.
The Mat you can get at the Sneak Preview
For further details on how to get both, check here.