My own pot roast

This is my first attempt at making a pot roast of my own. Usually this is Aaron's thing. But since he was sleeping after a night shift I thought I'd take a stab at it. I think I did well

2 Tbsp olive oil
4 lb pork shoulder roast (you can use less, that's just the size I had)
1 (8 oz) can tomato sauce
1 medium onion, cut into chunks
1/2 lb baby carrots
2 stalks celery, cut into chunks
3 medium potatoes, (skins on) cut into chunks
3 cloves garlic, chopped
2 bay leaves
fresh Parsley, finely chopped
fresh Basil, finely chopped
fresh Oregano, finely chopped
(I didn't really measure the fresh herbs, but I think it was about 1 tsp each.)
1 tsp salt
1/2 tsp pepper

Heat the oil in a large skillet. Sear the roast on all sides. Place in slow cooker. Add remaining ingredients. Cook on low 6-8 hours. I cooked it on low for 3 hours, and then after seeing the rawness of it. Cut the roast into about 6 chunks and cooked it on high for the last hour. It was done. If I could go back I would have liked to add more fresh herbs and used tomatoes instead of tomato sauce. I was worried I wouldn't have enough liquid, but the liquid came as everything cooked.