In Wednesday's NY Times Mark Bittman has a recipe for Welsh Rarebit which you may want to try. It has flour which should help with the thickening.
December 27, 2006
Recipe: Welsh Rarebit
Time: About 20 minutes, plus cooling
Adapted from Fergus Henderson
2 tablespoons butter
2 tablespoons flour
1 tablespoon mustard powder, or to taste
½ teaspoon cayenne, or to taste
¾ cup strong dark beer, like Guinness
2 tablespoons Worcestershire sauce, or to taste
1 pound Cheddar, Double Gloucester or other English cheese (or other good semi-hard cheese, like Comté or Gruyère, or a mixture), grated
4 to 8 pieces lightly toasted bread.
1. Put butter in a saucepan over medium heat and, as it melts, stir in flour. Continue to cook, stirring occasionally, until golden brown and very fragrant, 3 to 5 minutes. Stir in mustard and cayenne, then whisk in beer and Worcestershire sauce.
2. When mixture is uniform, turn heat to low and stir in cheese, again stirring until smooth. Remove from heat and pour into a broad container to set (you can refrigerate for up to a day at this point).
3. Spread mixture thickly on toast and put under broiler until bubbly and edges of toast are crisp. Serve immediately.
Yield: 4 or more servings.
Jyoti
A meal, with bread and wine, shared with friends and family is among the most essential and important of all human rituals.
Ruhlman