Preheat the oven to 375 degrees F. Butter twelve 4-ounce ramekins, then coat with ground tortilla chips (about 1/4 cup total). Combine the half-and-half, corn, the remaining 1/2 cup ground tortilla chips and 1 teaspoon salt in a medium saucepan over medium-high heat. Bring to a simmer and cook, stirring, until thick like pudding, about 2 minutes. Remove from the heat and whisk in 1/2 cup cheese.
Meanwhile, beat the eggs in a large bowl with a mixer on medium-high speed until thick and fluffy, 5 minutes. Whisk in half of the corn mixture until combined. Fold in the remaining corn mixture with a rubber spatula, then fold in the jalapeno, scallions and tomatoes.
Transfer the prepared ramekins to a baking sheet; divide the batter among the ramekins and sprinkle the tops with the remaining 1/4 cup cheese. Bake until the spoonbread is puffed and set, 20 to 25 minutes. Let cool 5 minutes. Top with pico de gallo.