Heat oil in a large saute pan or skillet over medium-high heat. Saute onions for a few minutes or until translucent, then throw in the peppers, garlic, salt, italian seasoning and optional cayenne. Saute for 6-7 minutes or until the peppers are soft. Remove veggies from the pan with a slotted spoon, leaving behind as much oil as possible.
Remove the sausage from it's casings and pull apart with your fingers. Throw into the pan and brown, breaking apart with a wooden spoon. When browned, drain the grease from the pan and add the veggies back in, along with the tomato paste. Stir to combine. Add half of the mozarella and stir again.
Pour the mixture into a large oven-proof skillet or pie pan. Top with the remaining mozarella.
Unroll the crescent dough and separate into triangles. Arrange in a spiral with the points of the dough towards the center, overlapping slightly to cover the sausage mixture completely. Press the dough to the edges of the pie pan to seal.
Bake for 12 minutes, or until the crust is golden brown.