Slice the onion into thick 'steaks' about 1/2" thick.
Push out the inner rings (save for another use), leaving the last two outer rings still together as one. Do not separate them. Note: If the rings are particularly thick then you can separate them as cook them as single rings.
Squeeze some Sriracha into a bowl that's just big enough to fit an onion ring.
Place the ring into the sauce. Using your fingers, spread the sauce all over the ring. Flip the onion and repeat. Get it coated, but not drenched.
Wrap bacon around the rings. Don't wrap too tightly since the bacon will shrink. Don't wrap it too loose or it'll fall off.
Brush (or just use your fingers) more Sriracha on the outside of the bacon.
Place the rings on your Big Easy rack and lower into the Big Easy.
Cook the rings until the bacon just starts to crisp. Gently flip them and cook another 10-15 minutes. Remove to a baking sheet and let firm up a bit.