Begin the game by searching the deck for a plain bread card and setting it down to begin the first sandwich, then shuffle the deck.

Set a turn order for the players, and on their turn the player must draw a card, and can hold a maximum of 3 cards in their hand.
However you cannot hold two of the same card (such as 2 tomatoes).
Though plain bread and top bread (the bread with the toothpick) count as different cards, and you can hold one of each.

Either play the card, or return it to a random position in the deck to get rid of excess or duplicate cards. In cases where a card cannot be played, then the only option will be to return it to the deck.

Playing a card, means setting down cards to build the sandwich, or using plain bread cards to start a new sandwich.
However you cannot place two of the same ingredients down in a row, and there must be at least 4 ingredients cards in between each bread card. So it’s recommended to arrange the card stacks so you can see at least the last 4 cards.

You can have more than one sandwich being built at once. And if you run out of sandwiches but still have cards left in the deck, you can search the deck for a plain bread card and set it down to start a new sandwich, or a player can set down a plain bread from their hand to continue the game.

Whoever places a top bread card (the bread card with the toothpick) on the top of a sandwich, claims that sandwich. With the number of cards that make up all sandwiches they managed to claim, being their point total.

The game ends when there are no more top breads to use, or no more cards left in the deck/player's hand on their turn. Any cards left over which are not part of a finished sandwich, do not count towards point totals and are to be discarded. 

 At the end of the game, whoever has the most cards wins.

Each round generally only lasts about 3-5 minutes. And it's typical to play multiple rounds within a game session.