1. Preheat oven to 425 degrees. In a 10-inch ovenproof nonstick skillet, heat oil over medium-high. Add eggs and chives, season with salt and pepper, and stir to combine. Dollop ricotta over the top. Cook, undisturbed, until edges are set, about 2 minutes. Transfer skillet to oven and bake until top of frittata is just set, 10 to 12 minutes. Invert or slide frittata onto a plate or cutting board. Serve warm or at room temperature.

2. Meanwhile, in a large skillet over high, bring 1 inch of salted water to a boil. Add asparagus and cook until bright green and tender, 2 to 4 minutes. Cut frittata into wedges and serve with asparagus.