For the salsa:
Place tomatoes, onion, jalapeno, garlic, and 2 tablespoons water in a blender and blend until smooth. Strain through a sieve.
Pour oil into a medium saucepan over mediumhigh heat. Add tomato mixture and simmer about 5 minutes, or until slightly reduced and thickened. Season with salt. Let cool to room temperature, then refrigerate until ready to serve.
For the filling:
Place potatoes in a large pot and cover completely with water. Season with a pinch of salt. Over high heat, bring to a boil and cook until tender, about 10 minutes. Drain and transfer to a mixing bowl.
In a small skillet over medium-high heat, warm vegetable oil. Saute chorizo 3 to 5 minutes, or until browned, stirring and breaking into pieces. Gently fold chorizo into potatoes. Stir in cheese until just combined. Form mixture into 8 equal balls. Place on a parchment-lined baking sheet and refrigerate at least 30 minutes.
For the masa:
Combine maseca, 1 3/4 cups water, and salt in a large mixing bowl and mix to form a ball. If it's dry and crumbly, add more water. Divide into 8 portions and flatten each into a disc large enough to wrap around 1 potato ball.
Fill a large, heavy pot with vegetable oil and heat to 365degreesF. Fry molotes, 2 at a time, 4 to 6 minutes, or until a light golden brown. Drain on paper towels and insert sticks. Top with cilantro and cotija cheese and serve with salsa.
* Maseca is corn flour that's been treated with lime.