Since I like teaching my specialty and miss doing so at Utrecht University (which first pensioned me off and then quit astronomy altogether) I am open to invitations to give similar undergraduate and graduate/postdoc courses on solar spectrum formation. The materials (displays, course notes, exercises) I use are found here. In 2021 I published an extensive overview in Compendium solar spectrum formation.
Consumer report: “Rutten, it is quick-mouth” (Google-translate).