Heat 1 tsp. olive oil in large, deep skillet over medium heat. Add mushrooms; cook and stir until mushrooms are tender, 5 to 7 minutes. Transfer mushrooms to a bowl and set aside.
Heat 2 Tbsp. olive oil in the skillet over medium heat. Season pork chops with salt and pepper and add to skillet, browning on both sides, 7 to 10 minutes. Place pork chops on a plate, then drain all but 1 tablespoon of drippings from the skillet. Stir in the garlic and onion; cook and stir until the onion has softened and turned translucent, about 5 minutes.
Add tomatoes, season with basil, oregano, salt, and pepper. Place pork chops back in the skillet; cover and simmer until pork chops are tender and cooked thoroughly, about 45 minutes. Stir in some water if the mixture becomes too dry. Place the bell pepper on top of the pork, then add the reserved mushrooms. Continue to simmer until the bell pepper is tender, 5 to 10 minutes.`