Wash the potatoes and peel if desired. I keep them unpeeled as it saves time and adds fiber and color to the final product.
Grate the potato, onion, and jalapeño pepper in a food processor or by hand. Place in a medium bowl. For less heat, remove seeds and membrane from pepper.
Mix in the egg, flour, baking powder, and salt. You might need to adjust the amount of flour.
Heat some oil in a large shallow pan over medium high heat.
Gently slide 1/3-1/4 cups of batter to pan and lightly press down to flatten.
Fry for about 4 to 6 minutes per side or until nicely browned.
Remove and drain on paper towels. Continue with remaining batter.
Serve hot/warm with sour cream.