For the charred tomato salsa: Preheat the broiler.
Halve the tomatoes and place skin-side down on a baking sheet. Drizzle with the olive oil and season with salt. Broil for 5 minutes, then add the garlic and jalapeno and broil until the vegetables are blistered and brown, another 5 to 7 minutes. Let cool for 5 minutes.
Put the tomatoes, garlic and jalapeno in a food processor and pulse a few times until combined but still chunky. Pour into a bowl and fold in the cilantro, lime juice and red onions.
For the zucchini frita: Heat a griddle over medium-high heat.
Slice the zucchini on a diagonal into 1/2-inch slices. Brush with the olive oil and season with salt and pepper. Griddle the zucchini slices until lightly golden, about 2 minutes per side.
Slit the Cuban buns and spread the butter on both sides. Place the buns buttered-side down on the griddle and cook until toasted.
Spread about 2 ounces of the charred tomato salsa on the bottom of each bun, then layer with cooked zucchini, another 2 ounces of salsa and the potato sticks. Top with the other half of each bun.
Recipe courtesy of Amanda Freitag