Homemade Gravy

1/2 c. butter
1 1/2 c. finely chopped onion
1/4 c. flour
1 tsp kosher salt
1/2 tsp pepper
2 c. turkey or chicken stock, heated
1 Tbsp heavy cream

In lg saute pan, cook butter and onions 12-15 min, until onions are lightly browned. Sprinkle flour into pan and whisk in, add salt and pepper. Cook for 2-3 min. Add stock and cook uncovered 4-5 min, until thickened. Add the cream and serve.