Special equipment: large nonstick skillet with a lid 2 1/4-inch round cookie cutters, optional
Mix the sour cream and herbs together, season with salt and pepper and set aside.
Put the bacon in a large nonstick skillet over medium-low heat and cook, stirring occasionally, until crisp and the fat has rendered out, 7 to 8 minutes. Remove the bacon from the skillet to a paper towel-lined bowl and set aside.
In the leftover bacon drippings, cook the leeks with a pinch of salt over medium-low heat until soft, about 6 minutes. Add the asparagus and jalapenos, season again with salt and cook, stirring until just tender, another 1 to 2 minutes. Remove from the skillet and set aside.
Whisk the eggs and half-and-half together, and sprinkle with 1 teaspoon salt and 1/2 teaspoon pepper. Wipe out the skillet and set over medium-low heat. Add 2 tablespoons butter and swirl around to coat the skillet. Once melted, add the egg mixture.
Sprinkle the bacon, sauteed vegetables, tomatoes, peas and roasted yellow peppers on top, making sure to evenly distribute everything over the eggs. Using your fingers, pinch off pieces of the goat cheese and sprinkle evenly around. Turn the heat to low and cover the pan. Let the frittata cook until the eggs are firm and no longer jiggly in the middle, 25 to 30 minutes.
Meanwhile, butter the potato buns with the remaining 4 tablespoons butter and toast until lightly golden.
Allow the frittata to rest for 10 minutes before slicing. Slide out onto a cutting board. Then, slice the frittata into squares the same size as your rolls. If you are looking for a fancier presentation, use a similar-size cookie cutter and punch out rounds of the frittata.
Place some of the herbed cream on the bottom of your bun, top with a piece of frittata, pile on some baby arugula and add the top bun.