Preheat the oven to 425 degrees.
In a small bowl, mix together the panko, parsley, and lemon zest. Add the olive oil and stir until the crumbs are evenly coated. Set aside.
Place the salmon fillets, skin side down, on a board. Generously brush the top of the fillets with mustard and mayo mixture (about 1 heaping teaspoon) and then sprinkle generously with salt and pepper. Press the panko mixture thickly on top of the mustard/mayo on each salmon fillet. The mustard and mayo will help the panko adhere.
Heat the vegetable oil over medium heat in a cast-iron skillet or large, heavy, ovenproof pan. When the oil is hot, add the salmon fillets, skin side down, and sear for 3 to 4 minutes, without turning, to brown the skin.
Transfer the pan to the hot oven for 5 to 7 minutes, until the salmon is almost cooked and the panko is browned. Remove from the oven, cover with aluminum foil, and allow to rest for 5 to 10 minutes. Serve the salmon warm, over a bed of French lentils. Garnish with lemon wedges.