theta rolls for phonologists

While Antony Worrall Thomson recommends spicing up your salads with henbane, the Linguist List has some alternative suggestions.

Assimilation Delish

Ingredients:
1 small vocalic system
2 voiceless obstruents
2 alveolar sibilants
1 tsp of homorganic riser

Cooking Instructions
First, carefully wash all vowels until all nasality disappears.
Fully open the mid-high vowels over a white cloth, and let them settle until the drift subsides. Heat up a large, non-stick syllabic structure (CCVCC works best). When smoking, carefully place all the vowels in cardinal order (important!) and let them lengthen a little. Place the voiceless obstruents in between the gaps, stirring slowly with a wooden palatograph. When the obstruents voice, place the alveolar sibilants on top of the front vowels and press firmly until all sibilants palatalize.
Remove from system before general unrounding occurs.
Accent to taste with homorganic riser and serve hot by itself or as an accompaniment to dialect soup.

Here.
See also Diglossia with Onion Rings and Post-Creole Continuum Roll

Apologies to the non-linguists.