Toss corn kernels and sliced bell pepper with lemon juice, olive oil and salt. Lightly mix 6 ounces ground beef chuck with a big pinch of kosher salt. Form into a ball, then shape into a 3/4-inch-thick patty; make an indentation in the center. Preheat a grill to high; brush the grates and burger with canola oil. Season the patty with salt and cumin and grill about 4 minutes per side.