Combine the shrimp, chili paste, salt, and garlic in a large bowl and toss to coat evenly. Set aside to marinate for 15 minutes at room temperature.
Preheat the oven to 425ºF. Grease a baking sheet with a bit of oil and set aside.
Toss the cauliflower with olive oil and a pinch of salt. Spread onto the baking sheet. Bake for 20-25 minutes.
While the cauliflower roasts, prepare the sauce for the cauliflower. Sauté the red onion in a tablespoon of olive oil over medium heat until soft and translucent, about 10 minutes. Add the tomatoes, salt, chicken stock, and gelatin. Simmer until reduced by half, another 10 minutes.
When the cauliflower is roasted, toss with the onion and sun-dried tomato sauce. Set aside.
Heat a large pan over medium-high heat. Add the pancetta and cook until the fat has rendered out, the meat is cooked through and beginning to brown, about 10 minutes. Transfer the pancetta to a paper towel lined plate to remove excess grease but leave as much in the pan as possible.
Add the seasoned shrimp and cook until opaque on the first side, then flip and cook the second side, about 2 minutes total. Off heat, stir in lemon juice and zest.
To serve, plate the shrimp atop the cauliflower mixture and add a bit more lemon zest and juice, if desired. Garnish with fresh parsley.