Preventing ClaimsTransformation from running on every HTTP request - iis

Question

I have a web application targeting .NET 5.0 and I am trying to implement Windows Authentication along with some policies for authorization. We have a database table from another application that holds info on user roles, so I am using that to set permissions for my users.
I created a ClaimsTransformer class:
ClaimsTransformer.cs
public class ClaimsTransformer : IClaimsTransformation
{
// snip constructor which pulls in my DbContext from DI
public async Task<ClaimsPrincipal> TransformAsync(ClaimsPrincipal principal)
{
var id = ((ClaimsIdentity) principal.Identity);
var ci = new ClaimsIdentity(id.Claims, id.AuthenticationType, id.NameClaimType, id.RoleClaimType);
// snip call to DbContext to get user's role from database
if (roleId == 1 || roleId == 7)
{
ci.AddClaim(new Claim("user-role", "admin"));
}
return new ClaimsPrincipal(ci);
}
}
I have my authentication/authorization setup like this:
Startup.cs
public void ConfigureServices(IServiceCollection services)
{
services.AddAuthentication(IISDefaults.AuthenticationScheme);
services.AddTransient<IClaimsTransformation, ClaimsTransformer>();
services.AddAuthorization(options =>
{
options.AddPolicy("Admin", policy =>
policy.RequireClaim("user-role", "admin"));
});
// snip rest of method
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
// snip unrelated code
app.UseAuthentication();
app.UseAuthorization();
}
My first use of this is to hide a menu in my _Layout.cshtml:
#if ((await AuthorizationService.AuthorizeAsync(User, "admin").Succeeded)
{
// Admin nav link
}
The issue is, since AuthorizeAsync is running on every HTTP request, my ClaimsTransformer also runs each time, hitting the database to check the user's roles on every request. I'd like to avoid this, but I'm not sure of the best way to do so.
Basically, I'd like the system to check the roles only once, when the user is first authenticated. I read that this is what is supposed to happen when using Windows Authentication with IIS, but I am seeing the roles query running on every request when deployed to my IIS server also.
I could easily add a check in my ClaimsTransformer to see if the "user-role" claim exists, and only hit the DB if it is not present, but is there a better way? Should I be overriding something like UserClaimsPrincipalFactory instead of using a ClaimsTransformer?