Preheat the oven to 425 degrees F. Spray the baking sheet with olive oil or avocado mist (you can also brush it all over the sheet. This helps the bottom of the taquitos to crispy up.).
Add the black beans, onion, pepper, garlic cloves, chili powder, paprika, cumin, cayenne, salt and pepper to a saucepan over medium-low heat. Add the stock and lime juice and stir. Simmer the beans uncovered, stirred occasionally, for 10 to 15 minutes, until the mixture starts to reduce and thicken. Set it aside to cool slightly. Remove the garlic cloves from the beans.
About 10 minutes before rolling the taquitos, slightly warm your tortillas so they don’t break. I do this either in the oven for 1 to 2 minutes, in the microwave for 10 to 15 seconds – you just want them more pliable so they roll. I suggest do 3 or so at a time.
Add 1 to 2 tablespoons of the black bean mixture into the center of the tortilla. Roll it up and place it seam-side down on the baking sheet. Repeat with the remaining tortillas and black beans. If you have leftover beans (you probably will!), they are excellent to serve on the side or to scoop up with chips! Spray the outsides of the tortillas with the oil mist (or brush them) – making sure the entire thing is covered.
Bake for 20 to 25 minutes, or until the tortillas are golden and super crunchy! Serve immediately with the avocado pico. I also like to serve with extra cilantro and shredded lettuce.