Potato, shrimp and corn papillotes

1 packet (368 g) of Champêtre parisian potatoes
1 lb (454 g) of peeled and deveined shrimps
2 corns
45 ml (3 tbsp.) of melted butter
Juice of half a lemon (+ lemon wedges for serving)
125 ml (½ cup) of chopped fresh parsley for garnish

Spice blend:
15 ml (1 tbsp.) of paprika
8 ml (½ tbsp.) of garlic powder
8 ml (½ tbsp.) of onion powder
4 ml (¼ tbsp.) of dried thyme
4 ml (¼ tbsp.) of dried oregano
8 ml (½ tbsp.) of cayenne pepper (to taste)
8 ml (½ tbsp) of sea salt
8 ml (½ tbsp) of black pepper