Make marinade. Combine shallots, garlic, ginger, and chiles in the small bowl of a food processor. Blend until the mixture is a thick paste. Stir in lemon juice, vegetable oil, paprika and salt
Make Piri-Piri Sauce. Heat 1/2 tbsp olive oil in a medium skillet over medium-high heat. Add sliced red pepper and sauté, stirring and turning frequently, until the skin starts to blister and blacken.
Sear Short Ribs. Switch on the Instant Pot to the sauté setting on high. When the instant pot is hot, pour about 2 tbsp of oil. When the oil is hot, working in batches, place 3-4 short ribs in the instant pot to sear - don’t overcrowd. Sear the short ribs on all sides, about 2-3 minutes per side. Remove seared short ribs to a plate.
Cook Short Ribs. Return seared short ribs to the Instant Pot, top with any excess marinade left in the resealable plastic bag you used to marinate them. Add 1 cup beef broth. Choose the manual high pressure function and set to high. Cook the short ribs for 45 minutes, followed by a 10 - 15 minute natural release.
Prepare Vegetables. While short ribs are cooking, toss sliced sweet potato with olive oil, salt and pepper, and spread out evenly on a parchment-lined baking sheet. Repeat with the Brussels sprouts on a second parchment-lined baking sheet.
Roast Vegetables. When there are 15 minutes of cook time left on the short ribs, put the sweet potatoes on a rack in the lower third of the oven. Bake for 30 minutes, flipping sweet potato fries halfway and moving to a rack in the top third of the oven.
Make Dijon Aioli. While vegetables are baking, prepare the Dijon aioli. Combine all ingredients in a small bowl and stir well.
Plate and serve. Once vegetables are done, remove short ribs from the Instant Pot and plate - topping with Piri-Piri Sauce. Add sweet potato fries and roasted Brussels sprouts to the plate - drizzle sprouts with dijon aioli and allow guests to add more, as desired.