Preheat oven to 350°F.
Preheat a large skillet over medium heat. In a bowl, mix red potatoes, 2 tablespoons oil, garlic powder, salt, cumin, paprika and chili powder. Add potato mixture to the hot skillet. Cook for 10-15 minutes until potatoes are fork tender.
Add yellow onion to skillet, cook an additional 3-5 minutes until onions are translucent. Add the beans and corn to the skillet. Add the juice from ½ of the lime to the skillet mixture. Combine, then remove from heat.
Take about 15 corn tortillas and place them on a parchment-lined baking sheet. It's okay if they overlap a bit. Place them in the oven for about 3-5 minutes until they are warm and soften up a bit. This will make them easier to roll without cracking.
Remove the tortillas from the oven. Spoon about ⅓ to ¼-cup of the potato filling into the center of each tortilla, then roll them up. Place each tortilla seam side down on the baking sheet. Repeat with the remaining tortillas until all of the filling is used.
Brush the tops of the taquitos with the remaining tablespoon of reserved oil.
Bake at 350°F for 15-20 minutes until the tortilla shells are light golden brown and crispy.
To make the avocado mash, add avocado, juice from the other ½ of the lime, and add a pinch of salt to a bowl. Mash with a fork. Top the taquitos with the avocado mash and sprinkle with fresh cilantro. Serve warm.
