Preheat the oven to 375 degrees F. Brush a parchment paper-lined baking sheet with the vegetable oil. Place the pecans on a plate. Combine the mayonnaise and 1 Tbsp. of the mustard in a bowl. Add the chicken and toss to coat. Coat the chicken in the pecans. Arrange in a single layer on the baking sheet. Bake for 10 minutes, and then turn over and bake 8 to 10 minutes more, or until cooked through. While this occurs, in a small bowl, mix the maple syrup with the remaining mustard. Arrange the chicken on a platter with the maple mustard dip alongside.
Note: Ground pecans are sold in the bulk foods aisle. Chicken breast fillets (the centre portion of the breast) are sold in the meat department. If not available, cut 3 to 4 boneless, skinless chicken breasts into 20 strips and use them.