01 - Preheat oven to 375°F. Position the rack in the center.
02 - In a large ovenproof skillet, heat olive oil over medium heat. Add asparagus, zucchini, and scallions. Sauté for 3 to 4 minutes until slightly tender.
03 - Stir in spinach and thawed peas. Cook for 1 to 2 minutes until spinach is fully wilted.
04 - In a mixing bowl, whisk together eggs, milk, salt, pepper, and thyme until well combined and uniform.
05 - Spread the sautéed vegetables evenly across the skillet. Pour the egg mixture over the vegetables. Gently shake the skillet to distribute evenly.
06 - Scatter crumbled goat cheese evenly across the top of the frittata.
07 - Cook on the stovetop without stirring over low to medium heat for 3 to 4 minutes, just until the edges begin to set.
08 - Transfer the skillet to the oven and bake for 12 to 15 minutes, or until the center is fully set and the top is lightly golden.
09 - Remove from the oven and cool slightly before slicing into wedges. Serve warm or at room temperature.