diff --git a/stimela/kitchen/recipe.py b/stimela/kitchen/recipe.py
index 9deaf1f..8f7ec6c 100644
--- a/stimela/kitchen/recipe.py
+++ b/stimela/kitchen/recipe.py
@@ -179,7 +179,7 @@ def do_assign(assignments):
             Substitution errors are ignored at this stage, a final round of re-evaluation with ignore=False is done at the end.
             """
             # flatten assignments
-            flattened = flatten_dict(assignments)
+            flattened = assignments # flatten_dict(assignments)
             # drop entries protected from assignment
             flattened = {name: value for name, value in flattened.items() if name not in self._protected_from_assign}
             # merge into recipe namespace
diff --git a/stimela/kitchen/step.py b/stimela/kitchen/step.py
index b0ecd84..7aea970 100644
--- a/stimela/kitchen/step.py
+++ b/stimela/kitchen/step.py
@@ -410,6 +410,8 @@ def run(self, backend: Optional[Dict] = None, subst: Optional[Dict[str, Any]] =
             skip = self._skip
             if self._skip is None and subst is not None:
                 skip = evaluate_and_substitute_object(self.skip, subst, location=[self.fqname, "skip"])
+                if skip is UNSET:  # skip: =IFSET(recipe.foo) will return UNSET
+                    skip = False
                 self.log.debug(f"dynamic skip attribute evaluation returns {skip}")
                 # formulas with unset variables return UNSET instance
                 if isinstance(skip, UNSET):