Coat a 10" skillet with 2 tablespoons olive oil and place over medium heat. Add diced onion and bell pepper. Cook, stirring occasionally, for about 4 or 5 minutes or until onion and bell pepper have softened. Add minced garlic and cook, stirring, for another minute. Add the cooked, chopped potatoes. Season the mixture with 1/2 teaspoon dried thyme, 1/2 teaspoon salt, and pepper to taste. Cook for another 4 to 5 minutes, until potato has lightly browned. Add chopped corned beef and cook just till corned beef has warmed, about 2 minutes. Press down on the hash with a spatula or wooden spoon to flatten down into the pan. Taste and season with additional salt and pepper, if desired. Remove from heat and set pan aside.