Fill a large pot with lightly salted water and bring to a rolling boil. Stir in angel hair pasta and return to a boil. Cook pasta uncovered, stirring occasionally, until tender yet firm to the bite, 4 to 5 minutes. Drain pasta and return to pot.
Slice whole lemon into circles; cut circles in half. Juice remaining half lemon; set aside.
Meanwhile, preheat a skillet over medium-high heat. Add enough chicken stock to cover bottom of the skillet. Add shrimp, 1 tablespoon butter, lemon slices, parsley, salt, and pepper; cook shrimp until bright pink on the outside and meat is opaque, about 4 minutes. Off heat, add tomatoes; cover skillet until tomatoes softened.
Add shrimp mixture to pasta; toss to combine. (You may take out the lemon slices and squeeze the juice out of them or simply keep them mixed in.)
Add more chicken stock to cover bottom of same skillet. Add remaining 1 tablespoon butter, more parsley, and reserved lemon juice; melt butter and simmer sauce. Toss sauce and Parmesan cheese into pasta until fully combined.
