Mexico's markets offer the best dried beans in the greatest variety of anywhere in the galaxy. My personal favorite are the Peruanos. They're sold mostly along the Pacific side of Mexico including the interior mainland, and you can get them in practically any size market. In dried form - in bag or bulk - they are the size and shape of small pinto beans, but whereas pintos are pinkish-tan with dark brown specks, Peruanos are a uniform pale greenish-yellow color. When cooked, Peruanos turn a light tan color. Their flavor is as delicate as their hue, milder than pinto beans with a creamier texture.
I'd love to include a photo of Peruanos to document their yummy yumminess. But I ate them all. The beans, not the photos. So go here to see what I'm talking about.
I haven't yet found Peruanos in any US market. I have no idea why not; they'd be popular with lots more than Mexican food. Below the fold you'll find GB's basic recipe for cooking Peruanos in a pressure cooker, though if you can't find any Peruanos you could experiment with another bean variety of your preference.
1/2 kilo (a bit over 1 lb.) of Peruanos
2 T dried ancho chiles
1 or 2 t vegetable oil, heated
1/4 C onion, chopped
3 cloves garlic, chopped
10 black peppercorns
5 or 6 dried bay leaves
1 t dried oregano
Soak the beans by keeping them covered in water for exactly 24 hours (or, depending upon the heat in your boat's cockpit, soak them there between 22 and 26 hours). This will yield about 1 quart of soaked beans, ready for cooking.
Chop the chiles into postage-stamp-sized chunks, and saute them gently in the vegetable oil until crisp - about 10 seconds should do. An alternative to the saute-with-oil would be to roast the chile chunks gently and quickly in a dry, covered skillet.
Dump the chile pieces and all the other ingredients into a pressure cooker. Add about 1 quart of water (roughly an equivalent volume that the beans had expanded to fill after they had soaked).
Turn the pressure cooker to 15 psi.
As soon as the cooker pressurizes, set a timer for 10 minutes.
After 10 minutes, immediately turn off the pressure cooker, depressurize it, taste your beans, then add salt if/as needed.