Heat broiler and arrange rack in middle of oven. Break eggs into a large bowl and beat until smooth. Stir in peas, tarragon, 1 teaspoon kosher salt and 1/4 teaspoon ground black pepper.

Heat oil in a large nonstick frying pan over medium-high heat. Once oil is shimmering, add onion and garlic and season with salt and pepper. Cook, stirring occasionally until vegetables are tender, but not brown.

Pour egg mixture over onions and stir ingredients together. Reduce heat to medium-low and cook until eggs are set around the outer inch of the pan, about 10 minutes. Transfer to the broiler and cook until puffed, browned and set in the middle, about 3 minutes. Slices into wedges and serve with a nice loaf of bread and a salad.