Bring a large pot of water to a boil then add the diced potatoes. Cook for about 5 to 7 minutes, just until soft. (Make sure to set a timer so they don’t overcook! You don’t want mushy potatoes.) Strain and set aside to cool.Preheat the oven to 400°F then line a baking sheet with parchment paper or a silicone mat.In a large bowl, whisk together minced garlic, mustard, lemon juice, oregano, olive oil, and salt & pepper. Once the potatoes have cooled, add them to the bowl and gently toss until evenly coated.Transfer the potatoes to the lined baking sheet. Space them out so that there is at least 1/2-inch between each. Bake in the oven for 20 to 25 minutes, until crispy and light golden brown. Serve warm and enjoy!