Wash chili, cut in half lengthwise, rinse rosemary, dab dry. Bring rosemary, chili, milk and cream to a boil and let steep.
Prepare dumplings according to package instructions, let cool and cut into 1 cm thick slices. Wash and peel vegetables. Halve kohlrabi, cut with carrots into 1/2 cm thick slices. Pre-cook vegetables in salted water for 5 minutes.
Heat oven to 200 degrees. Meanwhile, heat butter in a saucepan, sweat flour in it. Pour seasoning milk through a sieve.
Simmer for 5 minutes, stirring frequently. Let cool slightly, stir in eggs, season with salt and pepper.
Layer half of the dumpling and vegetable slices like roof tiles in a greased baking dish.
Sprinkle with half of the cheese. Place remaining vegetables and dumpling slices on top as a second layer. Pour béchamel sauce over the casserole, sprinkle with remaining cheese.
Bake the casserole in the oven at 200 degrees for 45 minutes.