For the turkey patties: In a large bowl, combine the turkey, ricotta, sage, soy sauce, Worcestershire sauce, Dijon and sprinkle with some salt and pepper. Divide into 4 equal patties and press them into 1/4-inch-thin rounds.
Heat a cast-iron griddle pan to medium-high heat.
Add the canola oil and sear the patties on the first side until golden brown, 3 to 4 minutes. Flip and cook for another 3 to 4 minutes until cooked through.
For the sandwich build: Place a slice of Swiss cheese on each piece of bread, then a turkey burger, followed by about 1/4 cup Caramelized Onions. Place the top piece of bread on and then butter each side of the sandwich.
Griddle each side over medium heat until golden, 2 to 3 minutes on each side. If you have a metal bowl, cover the sandwiches so they steam a bit and the cheese will melt faster. Serve with good ol' yellow mustard if you like and a big pile of oven fries.