Preheat oven to 450.
Slice the onion into ½ inch slices, separate the rings. Place in a large bowl of ice water. Allow to sit for at least 20 minutes (this will take the harsh “bite” out of the raw onion and help them cook better).
Add the Kettle chips to a food processor, process until only crumbs remain. Transfer crumbs to a bowl, drizzle with melted butter, toss to coat.
Drizzle a large baking sheet with about 1 tablespoon canola oil, set aside.
In a large bowl add 1 cup flour (reserve the other cup) and 1 teaspoon salt, stir to combine. Stir in the beer to make a smooth batter.
Add the remaining flour to a small bowl.
One at a time remove the onion slices from the water, dredge in flour until well coated, dip in the batter allowing excess batter to drip back into the bowl, then add to the Kettle chip crumbs to gently coat.
Add to prepared baking sheet in an even layer, making sure the onion rings aren’t touching (smaller rings can be place inside large ones as long as they don’t touch) drizzle with canola oil.
Bake at 450 for 10 minutes, gently flip, bake until golden brown on all sides, about 8 additional minutes.