In a medium bowl, whisk together eggs, milk, sugar, and salt. Mix in flour, 1/4 - 1/2 cup at a time, until a runny batter forms. Whisk in the oil and let rest for about 15 minutes.
In a 10 inch skillet or pan, rub a little oil and heat over medium low to medium. Once thoroughly heated, add 1/4 - 1/3 cup batter to the center and immediately tilt the pan in a circle to coat the bottom in a thin layer. Cook until bubbles begin to form and the bottom turns golden, about 2 minutes. Flip and cook until the other side is golden, 30 seconds to 1 minute. Remove to plate. Rub the pan with more oil and repeat with remaining batter.
Serve immediately with sour cream and jam or sweetened condensed milk.