Sage Chorizo Sweet Potato Naan Pizza



8 ounces chorizo
½ medium yellow onion, thinly sliced
large handful fresh sage leaves, chopped and divided
2 naan breads
8 ounces ricotta
1 tablespoon extra virgin olive oil
salt and pepper to taste
½ medium sweet potato, skin peeled then peeled into wide flat strips using a vegetable peeler
1 cup grated parmesan cheese