Question

1. the restaurants famous original dish is made of...?

chicken
beef
pig
fish

1. spain has a monarchy

just like the uk, spain has a royal family too! their current king is called felipe vi and has reigned since 2014.
again, much like the uk, the role of spains royal family is apolitical and neutral, with limited power. despite this, the king still carries out some important ceremonial duties.

1. madrid is home to the oldest restaurant in the world

sobrino de botín is a spanish restaurant in madrid, and the oldest restaurant in the world in continuous operation.
the restaurant was originally founded in 1725 by frenchman jean botín and his wife. it was originally called casa botín until one of his nephews took over the restaurant and renamed it sobrino de botín, a name that survives to this day.
the restaurant has kept the flame burning in its oven continuously, never to be extinguished. one of their famous original recipes is roast suckling pig and their

Explanation:

The text mentions "one of their famous original recipes is roast suckling pig". Suckling pig is made from pig.

Answer:

Pig