Preheat oven to 350 degrees Fahrenheit.
Mix together the olive oil, salt and pepper, tomatoes, and asparagus and mix until all the veggies are coated. Spread out on a foil-lined baking sheet and roast in the oven until the tomatoes are shriveled, about 10 minutes. Broil the veggies for 5 minutes, getting some of the tomatoes a little blistered.
Melt the butter in a nonstick skillet on medium-high heat. Add the garlic and arugula and cook for 2 minutes until it's wilted. Transfer to a bowl.
Whisk the eggs. Reheat the skillet on medium-low heat. Pour the eggs into the skillet and spoon the roasted tomatoes, asparagus, and arugula on top. Sprinkle with the extra-sharp cheddar cheese and dot with the sliced cheese and harissa (to your own personal taste and heat tolerance).
Cook until the edges have set (about 5 to 6 minutes). Transfer to the oven and bake 20 minutes or until cooked through.
Broil for 5 minutes, crisping and making the top crusty. Take out and let cool for a little and then use a spatula to transfer to a serving plate.
Eat by itself or serve on top of crusty bread spread with some harissa.