Cut breasts into nuggets, reserve trimmings. Mix all seasonings with 1 1/2 cups of flour and toss pheasant pieces to coat. Over medium heat in a heavy-bottom skillet, heat vegetable oil to the smoke point. Fry diced pheasant until golden brown. Add half of the butter to baste, season with salt and pepper and hold in warm oven. In a small saucepan, add 1 teaspoon oil and pheasant trimmings coated with flour. Add garlic, onion, and 1/4 cup of butter and flour, and wisk in milk. Cook until thick adding water as needed to thin to desired consistency. Serve with mashed potatoes.