Preheat oven to 400 degrees. Place 6 ramekins or small crocks on a baking sheet.
Place potato pieces into a pot of cold salted water over high heat and bring to a boil, allowing to boil for about 15 minutes. Once fork-tender, drain. Return potatoes to pan. Add milk, 1/4 teaspoon salt, and 1 tablespoon olive oil. Mash well.
Meanwhile, add 1/2 tablespoon olive oil to a pan over medium heat. Add the ground turkey and 1/4 teaspoon salt. Break up the meat and stir occasionally. Cook for 8 to 10 minutes until browned and completely cooked through. Drain any excess fat.
Add 1/2 tablespoon olive oil, onions, carrots, and thyme to the skillet. Cook for 5 to 6 minutes, until they have softened a bit. Add corn and peas and cook for an additional 5 minutes. Add the ground turkey to the vegetables, stirring to combine, and breaking up poultry as it cooks. Stir in worcestershire sauce (or balsamic vinegar), tomato paste, and broth. Cook for an additional 8 minutes. Form a space for the garlic, add in, cook for 30 seconds and stir in with the rest of the ingredients. Remove from heat.
Place the ground turkey mixture on the bottom of each ramekin. Top with cheddar cheese, if using, and the mashed potatoes, spreading evenly.
Bake for 20 minutes, then set broiler and place under for 3 minutes until top is golden. Handle hot ramekins carefully. Serve ramekins on individual plates as they will be too hot to handle. Enjoy!