Stuffed Mushrooms With Arugula, Walnuts, and Sun-Dried Tomatoes

INGREDIENTS

2 cups

Arugula

4 cups

Baby spinach

1 1/2

lbs Cremini mushrooms

5/8 cup

Flat-leaf parsley

2 tbsp

Garlic

1/3 cup

Red onion

1/2 cup

Sun-dried tomatoes, oil-packed

1 1/3 tbsp

Balsamic vinegar

1/4 tsp

Black pepper, freshly ground

1/2 tsp

Salt

3 tbsp

Olive oil

1 2/3 tbsp

Pine nuts

1/2 cup

Walnuts, toasted and finely chopped

1/2 cup

Panko bread crumbs