Cook and drain rice noodles according to package instructions.
In a small bowl, whisk together mirin, peanut butter, fish sauce, Sriracha, soy sauce, brown sugar, and 1 tablespoon sesame oil. (This will make a medium heat/spice pad Thai; adjust Sriracha to taste for spice level).
Heat sesame oil over medium heat in a saute pan. Add garlic paste, Thai paste, and shrimp. Saute shrimp for 2-3 minutes or until they are cooked through (for raw shrimp) and beginning to brown. Do not overcook the shrimp.
Remove shrimp to a plate.
Add cooked noodles and half of the sauce to the saute pan. Heat and toss to stir until the noodles are evenly coated with sauce. Add additional sauce as desired.
Place noodles on a serving platter. Top with shrimp, slivered carrots, green onions, chopped peanuts, cilantro, and a pinch of red pepper flakes.