Anticuchos de Corazon

Quite recently I became interested in learning some different ways to prepare beef heart, so I went to Google. This is what I learned:
1) Many people consider beef heart an ideal ingredient for homemade fish food. And apparently they don't seem to think it could be used for anything else because these recipes don't always state that the result is fish food (!)
2) Contrary to my expectation I couldn't find a single Mexican recipe using beef hearts. Most disappointing - I almost feel like making one up, as pseudo-Mexican as that would be.
3) One of the more popular dishes that does use beef heart is the Peruvian anticuchos de corazon, or loosely translated beef heart shish kabob. Makes me wonder if this dish has some kind of Incan roots to it. But I do know that quinoa was a staple food of the Incas - I've heard, though, that it's much less used in modern Peruvian cuisine - so I figured that would make a good side dish this time around.

Ingredients:
- 1 lb (0.5 kg) beef heart
- 4 dried puya chilies
- 2 fresh serrano chilies
- 1 fresh jalapeño chili
- 2 tbsp annatto seeds
- 1 garlic clove
- 1 tsp ground cumin
- 0.5 cup (100 mL) red wine vinegar
- 0.5 cup (100 mL) olive oil
- 2 tsp salt
- 1 small onion
- 2 zucchinis
- 1 red bell pepper
- 2 cups water
- 1 cup quinoa
- 1 leek
AND finally you'll need some................. .................bamboo skewers[1]

To make the marinade: Take the dried puya chilies, cut off the stem end and shake out most of the seeds, then place them in a small saucepan, just covered with water, bring this to a boil, remove from the heat and let sit 20 minutes to soften the dried chilies. The fresh chilies can simply be cleaned (seeds removed) and diced. Combine all the chilies with the annatto seeds, the garlic, the cumin, the vinegar and the salt - use a blender to make a purée, then add the oil and mix it well.
Take the meat and clean it well, that is: cut away all sinew and silverskin, then cut it in pieces roughly 1/3 - 1/2 inch thick and 1 - 2 inches long and marinade overnight. I personally prefer the famous ziplock bag marinade technique (see pictures) over the old fashioned in-a-covered-bowl-technique.[2]

Put the pieces of meat on bamboo skewers together with chunks of zucchini, onion and bell pepper. I grilled them using the broiler in my gas oven (took about 10-12 minutes on max heat).
Serve immediately. E.g. with ...

...Leek Quinoa Pilaf:
Cut a leek in 1 cm (1/2 inch) rings, rinse well, and stir with salt in preheated oil for a couple of minutes, then add the quinoa, mix well, add the water, bring to a boil, reduce the heat and let stand till water is absorbed.

[1] As the meal was almost ready one of my guests informed me that soaking the bamboo skewers in water for at least an hour prior to use reduces their tendency to burn. I'll have to try to remember that one for next time.
[2] However, this technique actually requires far less liquid for the same amount of meat so I think the marinade could probably be made on half the scale under these circumstances.