Shrimp Newburg in Patty Shells

4 frozen patty shells 1/4 C butter 1/4 C flour 1/2 tsp. each dried rosemary and thyme leaves 1/2 tsp. salt 1/4 tsp. black pepper 1 C milk 2 egg yolks, beaten 1 Tbsp. catsup 1/2 C half and half 3/4 lb. cooked and shelled shrimp 1/2 C peas, cooked and drained Prepare and bake frozen patty shells according to package directions. In med. saucepan, melt butter. Blend in flour over med. heat. Add seasonings. Cook, stirring, about 3 minutes. Remove from heat. Very gradually, add milk. Return to heat. Cook until bubbling, stirring frequently. Reduce heat to low. Combine egg yolks and catsup. Add 2 to 3 tsp. hot sauce to egg yolks, mixing. Stir into sauce. Heat over low heat until mixture thickens. Make sure heat is low enough to avoid curdling. Remove from heat. Whisk in half and half. When patty shells are ready, stir shrimp and peas into sauce. Ladle equal portions into patty shells. Serve.