Pipián Paste is a rich, thick, reddish-brown mole sauce made in Mexico used for pork, poultry, seafood and vegetables.
It is made from dried chile peppers such as pasilla and ancho (or mulato), cloves, garlic, oil, toasted pumpkin seeds, roasted peanuts (some recipes just call for peanut butter now), toasted sesame seeds,
A green variety, made with tomatillos and green peppers, is referred to as Pipián verde, or Mole verde.
If someone says just "Pipián", the version that is reddish brown is meant.
Individual cooks may vary the recipe, swapping in almonds for pumpkin seeds, and adding their own touch through herbs such as epazote.
You can buy it ready-made in jars. Unless the jar specifies otherwise, use 1 part of the ready-made paste to 4 parts of water or broth to thin down the paste.