Make Spring Onion Asparagus Frittata, a bright, herb-scented frittata perfect for brunch or a light dinner.
Preheat your oven to 375°F so it's ready when the assembled frittata goes in; this quick note gets the cooking environment set while you move through the prep. Treat this as a gentle nudge to have the oven hot and waiting so the eggs bake evenly once assembled.
In an 8-inch cast-iron or oven-safe non-stick skillet, warm a drizzle of olive oil over medium heat and lightly sauté the chopped spring onion whites and asparagus pieces with a pinch of salt and a grind of pepper until they are bright, slightly tender, and still vibrant—just a few minutes. Transfer the softened vegetables to a small bowl and set aside while you move on; their texture should be tender-crisp, not mushy.
Crack the eggs into a blender with the smashed garlic, a splash of water, and a little salt and pepper; blend briefly until the mixture is well combined and lightly foamy. This yields a silky, aerated egg base that will puff a touch in the oven and give the frittata a tender, uniform crumb.
Wipe out the skillet so it's clean, then coat it lightly with olive oil. Pour in the blended eggs and scatter half of the sautéed vegetables and half of the cheeses evenly over the surface so they sink slightly into the egg. Slide the skillet onto the table (not showing an oven) and bake briefly for 8–10 minutes until the edges begin to set and take on a faint golden rim but the center still looks glossy and slightly uncooked on top.

Carefully add the remaining vegetables and the rest of the cheeses to the semi-set surface—place them gently so the skillet isn't shaken—and return it to finish baking for another 10–15 minutes, until the edges are golden brown and the eggs are fully set and springy. The final interior should be creamy yet cooked through, with pockets of melted cheese and tender vegetable bites.
Remove the skillet, top the golden frittata with chopped tarragon, a fresh grind of black pepper, and a few red pepper flakes for color and a hint of heat. Let it cool briefly so the texture firms up for cleaner slices, then serve directly from the same cast-iron skillet.
