Season shrimp with blackened seasoning, salt*, and pepper.
Heat oil in a skillet over medium heat. Cook shrimp 2–3 minutes per side until opaque and scoot to the side of the pan.
Reduce heat to low, add butter and garlic, and saute until fragrant. Toss the shrimp around, coating them evenly in the garlic butter. Add a squeeze of lemon juice and sprinkle over parsley. Remove shrimp and set aside.
In the same pan, melt butter and sauté shallots and red chile until softened. Add garlic and cook 30 seconds.
Add white wine and simmer briefly. Pour in chicken stock, half & half, spinach, and linguine.
Bring to a gentle boil, then cover and cook on low 15–20 minutes until pasta is tender and sauce thickens.
Stir in parmesan, lemon zest, and lemon juice. Return shrimp to the pan and toss to combine. Cook a few more minutes until thickened. Sprinkle over extra parsley and red pepper flakes if desired.
Serve immediately with lemon wedges.