Add all ingredients to a medium-sized bowl and stir to combine.
Heat oven to 350°F.
Slice each loaf of bread in half lengthwise, then place in the oven directly on the grates. Toast until crispy and warm, about 3 minutes.
Add oil to a large skillet over medium-high heat. When oil is hot, add sausages cut-side down and sear for 5 minutes, or until golden brown. Flip all sausages and sear on the other side for 3 minutes. Sausages should be golden brown and heated through.
Divide remoulade evenly between the top slice of each sandwich. Add 2 sausage halves to each bottom slice of bread, then add lettuce, tomatoes, and pickles. Top with remoulade-coated top slice, then cut sandwich in half. Serve with onion rings.
