Crunchy Stuffed Chicken Breast

I made these as one of the main dishes for the Sunday night The Librarian: Return to King Solomon's Mines watching party. I made two sets, one with onions and one without. I can't speak to the one with onions, but the other was quite good. Here is the main recipe with a few notes on some of the changes I made. I thought I ended up with a lot more marinade and topping than I needed, but better too much than not enough.

Serves 4

4 boneless, skinless chicken breasts
2 Tbsp butter
1 garlic glove, crushed
I Tbsp Dijon mustard

For the stuffing
1 Tbsp butter
1 bunch scallions, sliced
3 Tbsp fresh breadcrumbs (I actually used seasoned dry ones as I had them on hand.)
2 Tbsp pine nuts (The next time I make these, I think I'll toast the pine nuts to alter the flavor profile a little.)
1 egg yolk
1 Tbsp chopped fresh parsley (Do NOT substitute dried for this as it will mess with the consistency of the stuffing.)
salt and black pepper
4 Tbsp grated cheese (I used Parmesan.)

For the topping
2 bacon slices, finely chopped (I actually used pancetta as I had it on hand.)
1 cup fresh breadcrumbs (Again, I used seasoned dry ones.)
1 Tbsp grated Parmesan cheese
1 Tbsp chopped fresh parsley

Preheat oven to 400. To make the stuffing, heat 1 Tbsp of the butter in a frying pan and cook the scallions until soft. Remove from heat and allow to cool for a few minutes. Add the remaining ingredients and mix thoroughly. To make the topping, fry the chopped bacon until crisp, drain and add to the breadcrumbs, Parmesan cheese and fresh parsley.

Carefully cut a deep pocket in each of the chicken breasts using a sharp knife. Divide the stuffing into fourths and use to fill the pockets. Put in a buttered ovenproof dish.

Melt the remaining butter, mix it with the crushed garlic and mustard and brush liberally over the chicken. Press on the topping and bake uncovered for about 30-40 minutes or until tender.