• 2 lb yukon gold potato, peeled and cut into 1/2 in (1 1/2 cm)
• cold water, for cooking potatoes
• 1 ½ tablespoons kosher salt, divided
• 1 ½ teaspoons freshly ground black pepper, divided
• 2 tablespoons unsalted butter, divided
• 1 tablespoon canola oil
• ½ small yellow onion, thinly sliced
• 8 oz cremini mushroom, steemed and quartered
• 1 small red bell pepper, seeded and diced
• 1 teaspoon fresh oregano, chopped
• 1 cup cherry tomato, halved
• 1 tablespoon fresh parsley, minced