Heat a large pan over medium heat and add oil. Once hot, sauté the onion until translucent.
Transfer half of the corn to a food processor and blend until smooth. Add the second half of the corn to the skillet with the onion and cook for 5-10 minutes.
Stir in dairy-free milk, sugar, and salt. Bring to a simmer and cook for about 10 minutes, stirring occasionally.
In the center of the skillet, melt the dairy-free butter and stir in flour, creating a roux. Add the reserved puréed corn to the skillet and stir to combine.
Reduce heat to low and continue to let simmer, stirring occasionally, until your desired thickness and creaminess is reached. Serve and enjoy!