In small bowl whisk together all ingredients for caper dill sauce until combined. Refrigerate until ready to use
In medium heavy saucepan over medium heat bring oil to 375 degrees. Slowly add sunchoke slices to hot oil. Cook stirring intermittently until lightly browned. About 5 minutes. Remove with a spider or slotted spoon to paper towel lined plate. Sprinkle with 1/4 teaspoon of kosher salt. Set aside.
Bring medium saucepan full of water to a boil. Add snap peas and cook for 1-2 minutes. Drain and place into medium sized serving bowl. Add butter, zest, and 1/4 teaspoon kosher salt. Toss lightly to combine and keep warm.
Pat fish gently with paper towels to make sure fillets are dry. Season with 1/4 teaspoons kosher salt, pepper, and oregano. Heat 2 teaspoons olive oil and 1 teaspoon canola oil in a nonstick pan over medium -high heat. When oil starts to shimmer but before smoking add fillets to pan carefully. Cook for 2 minutes each side taking care not to move the fish in between turning so you get beautiful browning. Remove from pan to paper towel lined plate.
Add 1/2 cup of peas to each plate. Top peas with tilapia and a dollop of caper dill sauce. Serve sunchoke chips on the side.
If you slice the sunchokes ahead of time make sure you store them in some ice cold water so they do not brown. Before frying make sure you pat them dry really well because water and hot oil do not mix and we don't want anyone to get hurt!