For the cheddar and herb scramble: Heat the canola oil over high heat in another cast-iron skillet. Add the cherry tomatoes cut-side down and cook until seared, 1 to 2 minutes. Season them with salt and pepper, and transfer to a plate.
Whisk together the eggs, Cheddar, chives, parsley and tarragon in a large bowl and sprinkle with salt and pepper. Heat the butter in a large nonstick pan over medium-low heat until it begins to sizzle. Add the egg mixture and slowly cook, stirring with a wooden spoon, until soft curds form. Remove from the heat and set aside.
For the popovers: Preheat the oven to 425 degrees F. Generously brush a 6-slot aluminum popover pan with softened butter. Place the pan in the oven to heat 5 minutes before you are ready to add the batter.
Whisk together the melted butter, flour, milk, salt, pepper and eggs until smooth. The batter should be thin. Fill the popover pans less than halfway full and bake for exactly 30 minutes. Do not open the oven door while popovers are baking. Make the popovers last because they need to be eaten almost immediately once removed from the oven.
For assembly: Open the popovers and fill each half with a slice of the bacon. Top each with the eggs, and a cherry tomato half. Serve the remaining tomatoes on the side.