I think the only "American" things are the foodways of displaced populations from different parts of the world colliding with each other in climates that required their palette of ingredients to shift and reconfigure.

it's a somewhat recent area of scholarship, mostly because it appreciates how domestic workers and farmworking families at the margins were the ones who lead the way in experimentation and intergenerational knowledge transfer of traditional food wisdom. notably, not elite chefs or wealthy patrons demanding "authentic" experiences from whatever old world they imagine is most fashionable to consume in that day.

most of mass produced / industrial foods were inspired by these innovations, but they are pale shadows of the real thing. it is the stubborn and multigenerational households of multi-ethnic influence that are still finding new permutations, combining Grandma's recipes with different vegetables that come from the nearby ethnic market nobody is connected to by descent. the East Asian family who makes Mediterranean influenced food, the West African guy who puts fried okra in burritos. the Indian grocery store that has more colors of lentils than there are in a rainbow alongside the spice aisle of the gods right in the middle of the historically Mexican neighborhood. just people getting weird where everything collides.

it's happening everywhere as peoples are displaced and dislocated and resisting the pressure to eat the shelf stable poison that comes in the box.