Preheat the broiler.
In a large mixing bowl, combine the tomatoes, corn kernels, jalapeno and shallot.
In a large (15-inch) oven-proof skillet, heat the oil over a medium-high flame. Transfer all but 1 cup of the corn salsa mixture to the pan and set the remaining aside for later. Sauté the vegetables until the shallot and corn are beginning to caramelize and the tomatoes have released their juices, about 5 minutes. Season with the cumin, paprika and 1/4 teaspoon salt. Cook for one more minute, until fragrant.
Meanwhile, in another large mixing bowl or 4-cup liquid measure, beat the eggs with 1/4 teaspoon salt until the yolk and whites are very well combined.
Reduce the heat to low and spread the cooked veggies in an even layer. Pour the beaten eggs over the top, making sure the pan is evenly coated with eggs. Cook over low heat until the sides are set and there’s just a shallow layer of uncooked eggs on the top, 5 minutes.
Transfer the pan to the broiler. Cook for 2 minutes, until the top is cooked and beginning to lightly brown. Remove from the oven and allow the frittata to sit in the pan for 5 minutes before slicing.
While the eggs rest, add the lime juice to the remaining corn salsa mixture and season with salt.
To serve, arrange the sliced avocado over the top of the frittata and garnish with the corn salsa and cilantro leaves. Cut into 4 wedges and enjoy warm or at room temperature.