In a saucepan, melt butter over medium heat. Add in onion and celery until tender. Whisk in flour until blended; cook and stir until golden brown.
Slowly add in the stock and milk while whisking. Bring to a boil, stir constantly and cook until thickened.
Add in cream cheese, peas, turkey, salt and pepper Cook until blended and heated through. For each serving, cut 2 slices of toast into triangles. Top with some of the turkey mixture followed by diced tomato. Serves 4.