Step 1: Prepare Potatoes - Peel and dice the russet potatoes into small cubes, about half an inch, rinse under cold water, and pat dry.

Step 2: Sauté Potatoes - Heat olive oil in a large skillet over medium heat, add potatoes, and sauté for 10-15 minutes until golden brown and crispy, seasoning with salt, pepper, cumin, and paprika.

Step 3: Add Flavors - Stir in the diced green chilies, minced garlic, and chopped red onion, continuing to sauté for another 3-5 minutes until the onion is tender.

Step 4: Assemble Tacos - Warm taco shells separately and fill each with potato mixture, optionally topping with shredded cheddar cheese.

Step 5: Garnish - Sprinkle freshly chopped cilantro over the tacos before serving.

Step 6: Serve - Plate the tacos while hot, serving with sour cream or Greek yogurt on the side.