Bring a large pot of water to a boil. Wash and dry produce.

Heat a large dry pan over medium-high heat. Add bacon; cook, turning occasionally and adjusting heat if browning too quickly, until crispy, 6-10 minutes.

Turn off heat; transfer to a paper-towel-lined plate. Carefully discard all but a thin layer of bacon fat from pan (you'll use it in Step 4). Once bacon is cool enough to handle, roughly chop.

Meanwhile, trim and discard woody bottom ends from asparagus; thinly slice stalks on a diagonal. Halve, peel, and thinly slice shallot. Thinly slice scallions, separating whites from greens.

Using your hands, gently separate rigatoni.

Once water is boiling, add rigatoni to pot. Cook, stirring occasionally, until al dente, 4-6 minutes.

Reserve ½ cup pasta cooking water (1 cup for 4 servings), then drain.

While pasta cooks, heat pan with bacon fat over medium-high heat. (TIP: If pan seems dry, add a drizzle of oil.) Add asparagus, shallot, and scallion whites; cook, stirring frequently, until browned and tender, 2-4 minutes.

To pan with veggies, add miso sauce concentrates, pork ramen stock concentrate, garlic powder, half the Sriracha, ½ cup plain water, and a pinch of sugar (all the Sriracha and ¾ cup plain water for 4 servings); stir to combine. Bring to a simmer, stirring occasionally.

Once sauce is simmering, add drained rigatoni and half the bacon. Cook, tossing, until pasta is evenly coated, 1-3 minutes. TIP: If sauce seems too thick, add reserved pasta cooking water 1 TBSP at a time.

Turn off heat; stir in sour cream, half the Parmesan, and 2 TBSP butter (4 TBSP for 4).

Divide pasta between bowls; top with remaining Parmesan, remaining bacon, and scallion greens. Serve.