Poach the chicken. Put chicken in a large stockpot and cover with gallon of room temp or cold water. Add veggies and herbs and boil over medium. Skim the fat and simmer uncovered for about 45 minutes.
Remove chicken from water and let cool. Strain liquid and reserve liquid - it's chicken stock! Shred chicken meat and discard both skin and bones.
Preheat oven to 325 degrees....Broiler on low works fine too.
Toast pecans until fragrant and give them a rough chop if you like.
Combine mayo, mustard, pecans, shallot, and parsley. salt and pepper to taste. Fold in shredded chicken!
Lightly paint bread with olive oil and toast until golden in oven. Smear 4 piece generously with plum butter. Take these plum butter smeared pieces and lay a slice (or good pile of finely shredded) of fontina cheese on top and pop back into the oven until cheese is just slightly melted. Top with a generous scoop of chicken salad and one romaine leaf. Cover with other half of bread to complete sandwich!