Place the potatoes in a saucepan, cover with cold water and salt the water. Bring to a boil and simmer 12 to 15 minutes, until tender. Drain thoroughly.

Heat 2 tablespoons oil in a skillet over medium heat. Cook the onion 3 to 4 minutes until softened; add garlic and cook 30 seconds. Mash into the potatoes with 1 teaspoon salt and pepper. Taste and adjust.

Warm the tortillas on a skillet or wrapped in a damp towel in the microwave until pliable. Spoon about 2 tablespoons potato filling onto one half of each and fold over.

Pour a shallow ¼-inch layer of oil into a skillet and heat over medium to medium-high heat until shimmering. In batches, add tacos carefully and fry 2 to 3 minutes per side, until golden and crisp. Drain on a rack or paper towels.

Serve hot with lettuce, crema, queso fresco and salsa.