Wash the tomatoes.
Make a criss cut cross on the bottom of the tomatoes.
Place on a hot skillet to roast.
After 5 minutes, turn to roast the other side.
Add the serrano peppers.
Roast for another 2 minutes.
Turn the peppers and the tomatoes to char all the sides.
Add the onion and garlic to the skillet.
Roast everything for an additional 2 minutes.
Remove the garlic and onions from the skillet.
Using a knife remove the skin from the garlic clove and set aside.
Remove the serranos and the tomatoes from the skillet.
Let cool slightly.
Remove the skin from the tomatoes.
Cut off the stems from the serranos and cut in half.
Dice the onion.
In a molcajete, add the dried chile piquin.
Grind until almost a powder.
Add the roasted garlic.
Grind until smooth.
Add the serrano peppers.
Grind until the peppers have been broken down.
Slowly add one tomato at a time. Pressing down gently so as not to squirt.
Mash it up.
Repeat with the second tomato.
Mash it up as well.
Add the roasted onion, salt, and cilantro.
Stir to combine.
Taste for salt and serve!